McGRAIN v. DAUGHERTY.

No. 28.

Argued December 5, 1924.

Decided January 17, 1927.

*137Mr. George W. Wickersham, Special Assistant to the Attorney General, with whom Attorney General Stone and Mr. William T. Chantland, Special Assistant to the Attorney General, were on the brief, for the appellant.

*144Messrs. Arthur I. Vorys and John P. Phillips, with whom Mr. Webb I. Vorys was on the brief, for the appellee.

*150Mr: Justice Van Devanter

delivered the opinion of the court.

This is .an appeal from the final order in a proceeding in habeas corpus discharging a recusant witness held in custody under process of attachment issued from the United States Senate in the course of an investigation which it was making of the administration of the Department of Justice. A full statement of the case is necessary.

The Department of Justice is one of the great executive departments established by congressional enactment and has charge, among other things, of the initiation and prosecution of all suits, civil and criminal, which may be brought in the right and name of the United States to compel obedience or punish disobedience to its laws, to recover property obtained from it by unlawful or fraudulent means, or to safeguard its rights in other respects; and also of the assertion and protection of its interests when it or its officers are sued by others. Xhe Attorney General is the head of the department, and its functions are all to be exercised under' his supervision and direction.1

Harry M. Daugherty became the Attorney General March 5, 1921, and held that office until March 28, 1924, *151when he resigned. Late in that period various charges of misfeasance and nonfeasance in the Department of Justice after he became its supervising head were brought to the attention of the Senate by individual senators and made the basis of an insistent demand that the department be investigated to the end that the practices and deficiencies which, according to the charges, were operating to prevent or impair its right administration might be definitely ascertained and that appropriate and effective measures might be taken to'remedy or eliminate the evil. The Senate regarded the charges as grave and requiring legislative attention and action. Accordingly it formulated, passed and invited the House of Representatives to pass (and that body did pass) two measures taking important litigation then in immediate contemplation out of the control of the Department of Justice and placing the same in charge of special counsel to be appointed by the President2; and also adopted a resolution authorizing and directing a select committee of five senators—

“ to investigate circumstances and facts, and report the same to the Senate, concerning the alleged failure of Harry M. Daugherty, Attorney General of the United States, to prosecute properly violators of the Sherman Anti-trust Act and the Clayton Act against monopolies and unlawful restraint of trade; the alleged neglect and failure of the said Harry M. Daugherty, Attorney General of the United States, to arrest and prosecute Albert B. Fall, Harry F. Sinclair, E. L. Doheny, C. R. Forbes, and their co-conspirators in defrauding the Government, as well as the alleged neglect and failure of the said Attorney General to arrest and prosecute many others for violations of Federal statutes, and his alleged failure *152to prosecute properly, efficiently, and promptly, and to defend, all manner of civil and criminal actions wherein the Government of the United States is interested as a party plaintiff or defendant. And said committee is further directed to inquire into, investigate and report to the Senate the activities of the said Harry M. Daugherty, Attorney General, and any of his assistants in the Department of Justice which would in any manner tend to impair their efficiency or influence; as representatives of the Government of the United States.”

.The resolution also authorized the committee to send for books and papers, to subpoena witnesses, to administer oaths, and to sit at such times and places as it might deem advisable.3

In the course of the investigation the committee issued and caused to be duly served on Mally S. Daugherty— who was a brother of Harry M. Daugherty and president of the Midland National Bank of Washington Court House, Ohio, — a subpoena commanding him to appear before the committee for the purpose of giving testimony bearing on the subject under investigation, and to bring with him the “ deposit ledgers of the Midland National Bank since November l, 1920; also note files and transcript of owners of every safety vault; also records of income drafts; also records of any individual account or accounts showing withdrawals of amounts of $25,000 or over during above period.” The witness failed to appear.

A little later in the course of the investigation the committee issued and caused to be duly served on the same witness another subpoena commanding him to appear before it for the purpose of giving testimony relating to the subject under consideration — nothing being *153said in this subpoena about bringing records, books or papers. The witness again failed to appear; and no excuse was offered by him for either failure.

The committee then made a report to the Senate stating that the subpoenas had been issued, that according to the officer’s returns — copies of which accompanied the report — the witness was personally served; and that he had failed and refused to appear.4 After a, reading of the report, the Senate adopted a resolution reciting these facts and proceeding as follows:5

“Whereas the appearance and testimony of the said M. S. Daugherty is material and necessary in order that the committee may properly execute the functions imposed upon it and may obtain information necessary as a basis for such legislative and other action as the Senate may deem necessary and proper: Therefore be it

“ Resolved, That the President of the Senate pro' tempore issue his warrant commanding the Sergeant at Arms or his' deputy to take into custody the body of the said ,M. S. Daugherty wherever found, and to bring the said M. S. Daugherty before the bar of the Senate, then and there to answer such questions pertinent to the mat- . ter, under inquiry as the Senate may order the President of the Senate pro tempore to propound; and to keep the said M. S. Daugherty in custody to await the further order of the Senate.”

It will be observed from the terms of the resolution that the warrant was to be issued in furtherance of the effort to obtain the personal testimony of the witness and, like the second subpoena, was not' intended to exact from him the production of the various records, books and papers named in the first subpoena:

The warrant was issued agreeably to the resolution and was addressed simply to the Sergeant at Arms. That *154officer on receiving the warrant endorsed thereon a direction that it be executed by John J. McGrain, already his deputy, and delivered it to him for execution;

The deputy, proceeding under the warrant, took the witness into custody at Cincinnati, Ohio, with the purpose of bringing him before the bar of the Senate as commanded; whereupon the witness petitioned the federal district court in Cincinnati for a writ of habeas corpus. The writ was granted and the deputy made due return setting forth the warrant and the cause of the detention. After a hearing the court held the attachment and detention unlawful and discharged the witness, the decision being put on the ground that the Senate in directing .the investigation and in ordering the attachment exceeded its powers under the Constitution, 299 Fed. 620. The deputy prayed and was allowed a direct appeal to this Court under § 238 of the Judicial Code as then existing.

We have given the case earnest and prolonged consideration because the principal questions involved are of unusual importance and delicacy. They are (a) whether the Senate — or the House of Representatives, both' being on the same plane in this regard — has power, through its own process, to compel a private individual to appear before it or one of its committees and give testimony needed to enable it efficiently to exercise a legislative function belonging to it under the Constitution, and (b) whether it sufficiently appears that the process was being employed in this instance to obtain testimony for that purpose.

Other questions are presented which in regular course should be taken up first.

The witness challenges the authority of the deputy to execute the warrant on two grounds — that there was no provision of law for a deputy, and that, even if there were such a provision, a deputy could not execute the *155warrant because it was addressed simply to the Sergeant at Arms. We aré of opinion that neither ground is tenable.

The Senate adopted in 1889 and has retained ever since a. standing order declaring that the Sergeant at Arms may appoint deputies “to serve process or perform uther duties ” in his stead, that they shall be “ officers of the Senate,” and that' acts done and returns made by them “ shall have like effect and be of the same validity as if performed or made by the Sergeant at Arms in person.” 6 In actual practice the Senate has given full effect to the order; and Congress has sanctioned the practice under it by recognizing the deputies — sometimes called assistants — as officers Of the Senate, by fixing their compensation and by making appropriations to pay them.7 Thus there was ample provision of law for a deputy.

The fact that the warrant was addressed simply to the Sergeant at Arms is not of special significance. His authority was not to be tested by the warrant alone. Other criteria were to be considered. • The standing order and the resolution under which the warrant was issued plainly contemplated that he was to be free to execute the warrant in person or to direct a deputy to execute it. They. expressed the intention of the Senate; and the words of the warrant were to be taken, as they well could be, in a sense which would give effect to that intention. Thus understood, the warrant admissibly could be executed by a deputy if the Sergeant at Arms so directed, which he did.

The case of Sanborn v. Carleton, 15 Gray 399, on.which the witness relies, related to a warrant issued to the Sergeant at Arms in 1860, which he deputed another to execute.. At that time there was no standing rule or *156statute permitting him to act through a deputy; nor was there anything in the resolution under which the warrant was issued indicative of a purpose to permit him to do so. All that was decided was that in the absence of a permissive provision, in the warrant or elsewhere, he could not commit its execution to another. The provision which was absent in that case and deemed essential is present in this.

The witness points to the provision in the Fourth Amendment to the Constitution declaring “no warrants shall issue but upon probable cause supported by oath- or affirmation ” and contends that the warrant was void because the report of the committee on which it was based was unsworn. We think the contention overlooks the relation of the committee to the Senate and to the matters reported, and puts aside the accepted interpretation of the constitutional provision.

. The committee was a part of the Senate, and its members were acting under their oath of office as senators. The matters reported pertained to their proceedings and were within their own knowledge. They had issued the subpoenas, had received and examined the officer’s returns thereon (copies- of which accompanied the report), and knew the witness had not obeyed either subpoena or offered any excuse for his failure to do so.

■ The constitutional provision • was not intended to establish a new principle but to affirm and preserve a cherished rule of the common law designed to prevent the issue of groundless warrants. In legislative practice committee reports are regarded as made under the sanction of -the-oath of office of its members; and where the mattérs reported are within the committee’s knowledge and constitute probable cause for an attachment such reports are acted on and given effect without requiring that they be supported by further oath or affirmation. This is *157not a new practice but one which has come down from an early period. It was well recognized before the constitutional provision was adopted, has been followed ever since, and appears never to have been challenged until, now. Thus it amounts to a practical interpretation, long continued, of both the original common law rule and the affirming constitutional provision, and should be given effect accordingly.8*

The principle underlying the legislative practice has also be§n recognized and applied in judicial proceedings. This is illustrated by the settled rulings that courts in dealing with contempts committed in their presence may order commitments without other proof than their own knowledge of the occurrence,9 and that they may issue attachments, based on their own knowledge of the default, where intended witnesses or jurors fail to appear in obedience to process shown by the officer’s return to have been duly served.10 A further illustration is found in the rulings that grand jurors, acting under the sanction of their oaths .as- such, may find and return indictments based solely on their own knowledge of the particular offenses, and that warrants may be issued on such indictments without further oath or affirmation;11 and still another is found in the practice which recognizes that where grand jurors, under their oath as such, report to the court that á witness brought before them has refused to testify, the *158court may act on that report, although otherwise unsworn, and order the witness brought before it by attachment.12

We think the legislative practice, fortified as it is by the judicial practice, shows that the report of the committee — which was based on -the committee’s own knowledge and made under the sanction of the oath of office of its members — was sufficiently supported by oath to satisfy the constitutional requirement.

The witness also points to the provision in the warrant and in the resolution under which it was issued requiring that he be'“brought before the bar of the Senate, then and there ” to give testimony “ pertinent to thé subject under inquiry,” and contends that an essential prerequisite to such an attachment was wanting, because he neither had been subpoenaed to appear and testify before the Senate nor had refused to do so. The argument in support of the contention proceeds on the assumption that the warrant of attachment “ is to be treated precisely the same as if no subpoena had been issued by the committee, and the same as if the witness had not refused to testify before the committee.” In our opinion the contention and the assumption are both untenable. The committee was acting for the Senate and under its authorization; and therefore the subpoenas which the committee issued and the witness refused to obey are to be treated as if issued by the Senate. The warrant' was issued as an auxiliary process.to compel him to give the testimony sought by the subpoenas; and its nature in this respect is not affected by the direction that his testimony be given at the bar of the Senate instead of before the committee. If the Senate deemed it proper, in view of his contumacy, to give that direction it was at liberty to do so.

*159The witness sets up an interlocutory injunction granted by a state court at Washington Court House, Ohio, in a suit brought by the Midland National Bank against two members of the investigating committee, and contends that the attachment was in violation of that injunction and therefore unlawful. The contention is plainly ill-founded. The injunction was granted the same day the second subpoena was served, but whether earlier or later in the day does not appear. All that the record discloses about the injunction is comprised in the paragraph copied in the margin from the witness’s petition for habeas corpus.13 But it is apparent from what is disclosed that the injunction did not purport to place any restraint on the witness, nor to restrain the committee from demanding that he appear and testify personally to what he knew respecting the subject under investigation; and also that what the injunction did purport to restrain has no bearing on the power of the Senate to enforce that demand by attachment.

*160In approaching the principal questions, which remain to be considered, two observations are in order. One is that we are not now concerned with the direction in the first subpoena that the witness produce various records, books and papers of the Midland National Bank. That direction was not repeated in the second subpoena; and is not sought to be enforced by the attachment. This was recognized by the court below, 299 Fed. 623, and is conceded by-counsel for the appellant. The other is that we are not now concerned-with the right of the Senate to propound or the . duty of the witness to answer specific questions, for as yet <no questions have been propounded to him. He- is asserting — and is standing, on his assertion — that the Senate is without power to interrogate him, even if the questions propounded be pertinent and ■otherwise legitimate — which for present purposes must be assumed.

The first of the principal questions — the one which the witness particularly presses on our attention — is, as before shown, whether the Senate — or the House of Representatives, both being on the same plane in this regard — has power, through its own process, to compel a private individual to appear before it or one of its committees and give testimony needed to enable it efficiently to exercise a legislative function belonging to it under the Constitution.

The Constitution provides for a Congress consisting of a Senate and House of Representatives and invests it with “all legislative powers” granted to the United States, and with power “ to make all laws which shall be necessary and proper ” for carrying into execution these powers and “all other powers” vested by the Constitution in the 'United States or in any department or officer thereof. • Art. I, secs 1, 8. Other provisions show that, while bills can become laws only after being considered and passed by both houses of Congress, each house is to be distinct *161from the other, to have its own officers and rules, and to exercise its legislative function independently.14 Art. I, secs. 2, 3, 5, 7. But there is no provision expressly investing either house with power to make investigations and exact testimony to the end that it may exercise its legislative function advisedly and effectively. So the question arises whether this power is so far incidental to the legislative function as to be implied.

In actual legislative practice power to secure needed information by such means has long been treated as an attribute of the power to legislate. It was so regarded in the British Parliament and in the Colonial legislatures before the American Revolution; and a like view has prevailed and been carried into effect in both houses of Congress and in most of the state legislatures.15

This power was both asserted and exerted by the House of Representatives in 1792, when it appointed a select committee to inquire into the St. Clair expedition and authorized the committee to send for necessary persons, papers and records. Mr. Madison, who had taken an important part in framing the Constitution only five years before, and four of his associates in that work, were members of the House of Representatives at the time, and all voted for the inquiry. ■ 3 Cong. Ann. 494. Other exertions of the power by the House of Representatives, as also by the Senate, are shown in the citations already made. Among those by the Senate, the inquiry ordered in 1859 respecting the raid by John Brown and his adherents on the armory and arsenal of the United States at Harper’s Ferry is of special significance. The resolution *162directing the inquiry authorized the committee to send for persons and papers, to inquire into the facts pertaining to the raid and the means by which it was organized and supported, and to report what legislation, if any, was necessary to preserve the peace of the country and protect the public property. • The resolution was briefly discussed and adopted without opposition. Cong. Globe, 36th Cong., 1st Sess., pp. 141, 152. Later on the committee reported that Thaddeus Hyatt, although subpoenaed to appear as a witness, had refused to do so; whereupon the Seriate ordered, that he be attached and brought before it to answer for his refusal. When he was brought in he answered by challenging the power o.f the Senate to direct the inquiry and exact testimony to aid it in exercising its legislative function. The question of power thus presented was thoroughly discussed by several'senators — Mr. Sumner of Massachusetts taking the lead in denying the power and Mr. Fessenden of Maine in supporting it. Sectional and party lines were put aside and the question was debated and determined with special regard to principle and precedent. The vote was taken orí a resolution pronouncing the witness’s answer insufficient and. directing that he be committed until he should signify that he was ready and willing to testify. The resolution was adopted — 44 senators voting for it and 10 against. Cong. Globe, 36th Cong., 1st Sess., pp. 1100-1109, 30,06-3007. The arguments advanced in support of the power are fairly reflected by the following excerpts from the debate:

Mr. Fessenden óf Maine. “ Where will you stop ? Stop, I say, just at that point where we have gone far enough to accomplish the purposes for which we were created; and these purposes are defined in the. Constitution. What are they? The great purpose is legislation. There are some other things, but I speak of legislation as the principal purpose. ■ Now, what do we propose to do here? We *163propose to legislate upon a given state of facts, perhaps, or under a given necessity. .Well, sir, proposing to legislate, we want information. We have it not ourselves. It is not to be presumed that we know everything; and if any body does presume it, it is a very great mistake, as we know by experience. We want information on certain subjects. How are we to get it? The Senator says, ask for it. I am ready to ask for it; but suppose the person whom we ask will not give it to us: what then? Have we not power to compel him to come before us? Is this power, which has been exercised by Parliament, and by all legislative bodies down to the present day without dispute — the power to inquire into subjects upon which they are disposed to legislate — lost to us? . Are we not in. the possession of it? Are we deprived of it simply because we hold our power here under a Constitution which defines what cur duties are, and what we are called upon to do?

“ Congress have appointed committees after committees, time after time, to make inquiries on subjects of legislation. Had we not power to do it? Nobody, questioned our authority to do it: We have given them authority to send for persons and papers during the recess. Nobody questioned our. authority. We appoint committees during the session,.,with power to send for persons and papers. Have we not that authority, if necessary to. legislation?

*****

“ Sir, with regard to myself, all I have to inquire into is: is this a legitimate and proper object, committed to me under the Constitution; and then, as to the mode of accomplishing it, I am ready to use judiciously, calmly, moderately, all the power which I believe is necessary and inherent, in order to do that which I am appointed to do; and, I take it, I violate no rights, either of the people generally or of the individual, by that course.”

*164Mr. Crittenden of Kentucky. “ I come now to a question where the cooperation of the two branches is not necessary. There are some things that the Senate may do. How? According to a mode of its own. Are we to ask the other branch of the Legislature to concede by law to us the power of making such an inquiry as we are now making? Has not each branch the right to make what inquiries and investigation it thinks proper to make for its own action? Undoubtedly. You say we must have a law for it. Can we have a law? Is it not, from the very nature of the case, incidental to you as- a Senate, if you, as a Senate, have the power of instituting an inquiry and of proceeding with that inquiry? I have endeavored to show that we have that power. We have a right, in consequence of it, a necessary' incidental power, to summon witnesses, if witnesses are necessary. Do we require the concurrence of the other House to that? It is a power of our own. If you have a right to do the thing of your own motion, you must have all powers .that are necessary to do it.

“ The means of carrying into effect by law all the granted powers, is given where legislation is applicable and necessary; but there are subordinate matters, not amounting to laws; there are inquiries of the one House or the other House, which each House has a right to conduct; which each has, from the beginning, exercised the power to conduct; and each has, from the beginning, summoned witnesses. This has been the practice of the Government from the beginning; and if we have a right to. summon the witness, all the rest follows as a matter of course.”

The deliberate solution of the question on that occa.sion has been accepted and followed on other occasions by both houses of Congress, and never has been rejected or questioned by either.

*165The state courts quite generally have held that the power to legislate carries with it by necessary implication ample authority to obtain information needed in the rightful exercise of that power, and to employ compulsory process for the purpose.

In Burnham v. Morrisey, 14 Gray 226, 239, the Supreme Judicial Court of Massachusetts, in sustaining an exertion of this power by one branch of the legislature of that Commonwealth, said:

“ The house of representatives has many duties to perform, which necessarily require it to receive evidence and examine witnesses. ... It has often occasion to acquire certain knowledge of facts, in order to the proper performance of legislative duties. We therefore think it clear that it has the constitutional right *to take evidence, to summon witnesses, and to compel them to appear and testify. This power to summon and examine witnesses it may exercise by means of committees.”

In Wilckens v. Willet, 1 Keyes 521, 525, a case which presented the question whether the House of Representatives of the United States possesses this power, the Court of Appeals of New York said:

“ That the power exists there admits of no doubt whatever. It is a necessary incident to the sovereign power of making laws; and its exercise is often indispensable to the great end of enlightened, judicious and wholesome legislation.”

In People v. Keeler, 99 N. Y. 463, 482, 483, where the validity of a statute of New York recognizing and giving effect to this power was drawn in question, the Court of Appeals approvingly quoted what it had said in Wilckens v. Willet, and added:

“ It is difficult to conceive any constitutional objection which can be raised to the provision authorizing legislative committees to take testimony and to summon *166witnesses. In many cases it may be indispensable to intelligent and effectual legislation to ascertain the facts which are claimed to give rise to the necessity for such legislation, and the remedy required, and, irrespective of the question whether in the absence of a statute to that effect either house would have the power to imprison a recusant witness, I cannot yield to the claim that a .statute authorizing it to enforce its process in that manner is in excess of the legislative power. To await the slow process of indictment and prosecution for a misdemeanor, might prove quite ineffectual, and necessary legislation might be obstructed, and perhaps defeated, if the legislative body had no other and more summary means of. enforcing its right to obtain the required information. That the power may be abused, is no ground for denying its existence. It is a limited power, and should be kept within its proper bounds; and, when these are exceeded, a jurisdictional .question is presented which is cognizable in the courts.” . . . “ Throughout this Union the practice of legislative bodies, and in this State, the statutes existing at the time the present Constitution was adopted, and whose validity has never before been questioned by our courts, afford strong arguments in favor of the recognition of the right of either house to compel the attendance of witnesses for legislative purposes, as one which has been generally conceded to be an appropriate adjunct to the power of legislation, and one which, to say the least, the State legislature has constitutional authority to regulate and enforce by' statute,”

Other decisions by state courts recognizing and sustaining the legislative practice are found in Falvey v. Massing, 7 Wis. 630, 635-638; State v. Frear, 138 Wis. 173; Ex parte Parker, 74 S. C. 466, 470; Sullivan v. Hill, 73 W. Va. 49, 53; Lowe v. Summers, 69 Mo. App. 637, 649-650. An instructive decision on the question is also found in Ex parte Dansereau (1875), 19 L. C. Jur. 210, where the *167legislative assembly of. the Province of Quebec was held to possess this power as a necessary incident of its power to legislate.

We have referred to the practice of the two houses of Congress; and we now shall notice some significant congressional enactments. May 3, 1798, c. 36, 1 Stat. 654, Congress provided that oaths or affirmations might be administered to witnesses by the President of the Senate, the Speaker of the House of Representatives, the chairman of a committee of the whole, or the chairman of a select committee, “ in any case under their examination.” February 8, 1817, c. 10, 3 Stat. 345, it enlarged that provision so as to include the chairman of a standing committee. January 24, 1857, c. 19, 11 Stat. 155, it passed “An Act more effectually to enforce the attendance of witnesses on the summons of either house of Congress, and to compel them to discover testimony.” This act provided, first, that any person summoned as a witness to give testimony or produce papers in any matter under inquiry before either house of Congress, or any committee of either house, who should wilfully make default, or, if appearing, should refuse to answer any question pertinent to the inquiry, should, in addition to the pains and penalties then existing,16 be deemed guilty of a misdemeanor and be subject to indictment and punishment as there prescribed; and secondly, that no person should be excused from giving evidence in such an inquiry on the ground that it might tend to incriminate or disgrace him, nor be held to answer criminally, or be subjected to any penalty or forfeiture, for any fact or act as to which he was required to testify, excepting that he might be subjected to prosecution for perjury committed while so testifying. January 24, 1862, c. 11, 12 Stat. 333, Congress modified the immunity provision in particulars not mate*168rial here. These enactments are now embodied m §8 101-104 and 859 of Revised Statutes. They show very plainly that Congress intended thereby (a) to recognize the power of either house to institute inquiries and exact evidence touching subjects within its jurisdiction and on which it was disposed to act;17 (b) to recognize that such inquiries may be conducted through committees; (c) to subject defaulting and contumacious witnesses to indictment.and punishment in the courts, and thereby to enable either house to exert the power of inquiry “ more effectually”;18 and (d) to open the way for obtaining evidence in such an inquiry, which otherwise could not be obtained, by exempting witnesses required to give evidence therein from criminal and penal prosecutions in respect of matters disclosed by their evidence.

Four decisions of this Court are cited and more or less relied on, and we now turn to them.

The first decision was in Anderson v. Dunn, 6 Wheat. 204. The question there was whether, under the Constitution,- the House of Representatives has power to attach and punish a person other than a member for con*169tempt of its authority — in fact, an attempt to bribe one of its members. The Court regarded the power as essential to the effective exertion of other powers expressly granted, and therefore as implied. The argument advanced to the contrary was that as the Constitution expressly grants to each house power to punish or expel its own members and says nothing about punishing others, the implication or inference, if any, is that power to punish one who is not a member is neither given nor intended. The Court answered this by saying:

(p. 225) “ There is not in the whole of that admirable instrument, a grant of powers which does not draw after it others, not expressed, but vital to their exercise; not substantive and independent, indeed, but auxiliary and subordinate.”

(p. 233) “This argument proves too much; for its direct application would lead to annihilation of almost every power of Congress. To enforce its laws upon any subject without the sanction of punishment is obviously impossible. Yet there is an express grant of power; to punish in one class of eases and one only, and all the punishing power exercised by Congress in any cases, except those which relate to piracy and offenses against the laws of nations, is derived from implication. Nor did the idea ever occur to any one, that the express grant in one class of cases repelled the assumption of the punishing power in any other. The truth is, that the exercise of the powers given over their own members, was of such a delicate nature, that a constitutional provision became necessary to assert or communicate it. Constituted, as that body is, of the delegates of confederated States, some such provision was necessary to guard against then-mutual jealousy, since every proceeding against a representative would indirectly affect the honour or interests of the state which sent him,”

*170The next decision was in Kilbourn v. Thompson, 103 U. S. 168. The question- there was whether the House of Representatives had exceeded its power -in directing one of its committees to make a particular investigation. The decision was that it had. The principles announced and applied in the case are — that neither house of Congress. possesses a “ general power of making inquiry into the private affairs of the citizen ”; that the power actually possessed is limited to inquiries relating to matters of which the particular house “has jurisdiction” and in respect of which it rightfully may take other action; that if the inquiry relates to “ a matter wherein relief or redress could be had only by a judicial proceeding ” it is not within the range of this power, but must be left to the courts, conformably to the constitutional separation of governmental powers; and that for the purpose of determining the essential character of the inquiry recourse may be had to the resolution, or order under which it is made. The court examined the resolution which was the basis of the particular inquiry, and ascertained therefrom that-the inquiry related to a private real-estate pool or partnership in the District of Columbia. Jay Cooke & Co. had had an interest in the pool, but had become bankrupts, and their estate was in course of administration in a federal bankruptcy court in Pennsylvania. The United States was one of 'their creditors. The trustee in-the bankruptcy proceeding had effected a settlement of the bankrupts’ interest in the pool, and of course his action was subject to examination and approval or disapproval by the bankruptcy court. Some of the creditors, including the United States, were dissatisfied with the settlement. In these circumstances, disclosed in the-preambl’e, the resolution directed the committee “ to inquire into the matter and history of said real-estate pool and the character of said settlement, with the amount of property involved in which Jay Cooke & Co. *171were interested, and the amount paid or to be paid in said settlement, with power to send for persons and papers and report to the House.” The Court pointed out that the resolution contained no suggestion of contemplated legislation; that the matter was one in respect to which no valid legislation could be had; that the bankrupts’ estate and the trusteé’s settlement were still pending in the bankruptcy court; and that the United States and other creditors were free to press their claims in that proceeding. And on these grounds, the Court held- that in undertaking the investigation “ the House of Representatives not only exceeded the limit of its own authority, but assumed power which could only be properly exercised by another branch , of the government, because it was in its nature clearly judicial.”

The case has been cited at times, and is cited to us now, as strongly intimating, if not holding, that neither house of Congress has power to make inquiries and exact evidence in aid of contemplated legislation. There are expressions in the opinion which, separately considered, .might bear such an interpretation; but that this was not intended is shown by the immediately succeeding statement (p. 189) that “ This latter proposition is one which we do not propose to decide in the present case because we are able to decide the case without passing upon the existence or non-existence of such a power in aid of the legislative function.”

Next in order is In re Chapman, 166 U. S. 661. The inquiry there in question was conducted under a resolution of the Senate and related to charges, published in the press, that senators were yielding to corrupt infhiences in considering a tariff bill then before the Senate and were speculating in stocks the value of which would be affected by pending amendments to the bill. Chapman appeared before the committee in response to a subpoena, but refused .to answer questions pertinent to the inquiry, and *172was indicted and convicted under the act of 1857 for his refusal. The Court sustained the constitutional validity of the act of 1857, and, after referring to the constitutional provision empowering either house to punish its members for disorderly behavior and by a vote of two-thirds to expel a member, held that the inquiry related to the integrity and fidelity of senators in the discharge of their duties, and therefore to a matter “ within the range of the constitutional powers of the Senate ” and in respect of which it could compel witnesses to appear and testify. In overruling an objection that the inquiry was without any defined or admissible purpose, in that the preamble and resolution made no reference to any contemplated expulsion, censure, or othér action by the Senate, the Court held that they adequately disclosed a subject-matter of which the Senate had jurisdiction, that it was not essential'that the Senate declare in advance what it meditated doing, and that the assumption could not be indulged that the Sénate was making the inquiry without a legitimate object.

The case is relied on here as fully sustaining the-power of either house to conduct investigations and exact testimony from witnesses for legislative purposes. In the course of the opinion (p. 671) it is said that disclosures by witnesses may be compelled constitutionally “ to enable the respective bodies to discharge their legitimate functions, and that it was to effect this that the act of 1857 was passed”; and also “We grant that Congress could not divest itself, or either of its houses, of the essential and inherent power to punish for contempt, in cases to which 'the power of either house properly extended; but, because Congress, by the act of 1857, sought to aid each of the houses in the discharge of its constitutional functions, it does not follow that any delegation of the power in each to punish for contempt was involved.” The terms “ legitimate functions ” and “ constitutional functions ” *173are broad and might well be regarded as including the legislative function, but as the case in hand did not call for any expression respecting that function, it hardly can be said that these terms were purposely used as including it.

The latest case is Marshall v. Gordon, 243 U. S. 521. The question there was whether the House of Representatives exceeded its power in punishing, as for a contempt of its authority, a person — not a member — who had written, published and sent to the chairman of one of its com- • mittees an ill-tempered and irritating letter respecting the action and purposes of the committee. Power to make inquiries and obtain evidence by compulsory process was not involved. The Court recognized distinctly that the House of Representatives has implied power to punish a person not a member for contempt, as was ruled in Anderson v. Dunn, supra, but held that its action in this instance was without constitutional justification. The decision was put on the ground that the letter, while offensive and vexatious, was not calculated or likely to affect the House in any of its proceedings or in the exercise of any of its functions — in short, that the act which was punished as a contempt was not of such a character as to bring it within the rule that an express power draws after it others which are necessary and appropriate to give effect to it.

While these cases are not decisive of the question we are considering, they definitely settle two propositions which we recognize as entirely sound and having a bearing on its solution: One, that the two houses of Congress, in their separate relations, possess not only such powers as are expressly granted to them by the Constitution, but such auxiliary powers as are necessary and appropriate to make the express powers effective; and, the other, that neither house is invested with “general” power to inquire into private affairs and compel disclo*174sures, but only with such limited power of inquiry as is shown to exist when the rule of constitutional interpretation just stated is rightly applied. The latter proposition has further support in Harriman v. Interstate Commerce Commission, 211 U. S. 407, 417-419, and Federal Trade Commission v. American Tobacco Company, 264 U. S. 298, 306-306.

With this review of the legislative practice, congressional enactments and court decisions, we proceed to a statement of our conclusions' on the question.

We are of opinion that the power of inquiry — with process to enforce it — is an essential and appropriate • auxiliary to the legislative function. It was so regarded and employed in American legislatures before the Constitution was framed and ratified. Both houses of Congress took this view of it early in their history — the House of Representatives with the approving votes of Mr. Madi-. son and other members whose service in the convention which' framed the Constitution gives special significance to their action — and both houses have employed the power accordingly up to the present time. The acts of 1798 and 1857, judged by their comprehensive terms, were intended to recognize the existence of this power in both houses and to enable them to employ it “more effectually ” than before. So, when their practice in the matter is appraised according to the circumstances in which it was begun and to those in which it has been continued, it falls nothing short of a practical construction, long continued, of the constitutional provisions respecting their powers, and therefore should be taken as fixing the meaning of those provisions, if otherwise doubtful.19

*175We are further of opinion that the provisions are not of doubtful meaning, but, as was held by this Court in the cases we have reviewed, are intended to be effectively exercised, and therefore to carry with them such auxiliary powers as are necessary and appropriate to that end. While the power to exact information in aid of the legislative function was not involved in those cases, the rule of interpretation applied there is applicable here. A legislative body cannot legislate wisely or effectively in the absence of information respecting the conditions which the legislation is intended to affect or change; and where the legislative body does not itself possess the requisite information — which not infrequently is true — recourse must be had to others who do possess it. Experience has taught that mere requests for such information often are unavailing, and also that information which is volunteered is not always accurate or complete; so some means of compulsion are essential to obtain what is needed. All this was true before and' when the Constitution was framed and adopted. In that period the power of inquiry —with enforcing process — was regarded and employed as a necessary and appropriate attribute of the power to legislate — indeed, was treated as inhering in it. Thus there is ample warrant for thinking, as we do, that the constitutional provisions which commit the legislatives function to the two houses are intended to include this attribute to the end that the function may be effectively exercised.

The contention is earnestly made on behalf of the witness that this, power of inquiry, if sustained, may be abusively and oppressively exerted. If this be so, it affords no ground for denying the power. The same con- • tention might be directed against the power to legislate,' and of course would be unavailing. We must assume, for present purposes, that neither house will be disposed to exert the power beyond its proper bounds, or with*176out due regard to the rights of witnesses. But if, contrary to this assumption, controlling limitations or restrictions are disregarded, the decisions in Kilbourn v. Thompson and Marshall v. Gordon point to admissible measures of relief. And it is a necessary deduction from the decisions in Kilbourn v. Thompson and In re Chapman that a witness rightfully may refuse to answer where' the bounds of the power are exceeded or the questions are not pertinent to the matter under inquiry.

We come now to the question whether it sufficiently appears that the purpose for which the witness’s testimony was sought was to obtain information in aid of the legislative function. The court below answered the question in the negative and put its decision largely on this ground, as is shown by the following excerpts from its opinion (299 Feet 638, 639, 640):

“ It will be noted that in the second' resolution the Senate has expressly avowed that the investigation is in aid of other action than legislation. Its purpose is to ‘ obtain information necessary as a basis for such legislative and other action as- the Senate may deem necessary and proper.’ This indicates that the Senate is contemplating the talcing of action other than legislative, as the outcome of the investigation, at least the possibility of so doing. The extreme personal cast of the original resolu-' tions; the spirit of hostility towards the then Attorney General which they breathe; that it was not avowed that legislative action was had in view until after the action of the Senate had been, challenged; and that the avowal then was coupled with an avowal that other action was had in view — are calculated to create.the impression that the idea of legislative action being in contemplation was an afterthought.

“ That the Senate has in contemplation the possibility of taking action other than legislation as an outcome of the investigation, as thus expressly avowed, would seem *177of itself to invalidate the entire proceeding. But, whether so or not, the Senate’s action is invalid and absolutely void, in that, in ordering and conducting the investigation, it is exercising the judicial function, and power to exercise that function, in such a case as we have here, has hot been conferred upon it expressly or by fair implication. What it is proposing to do is to determine the guilt of the Attorney General of the shortcomings and wrongdoings set forth in the resolutions. It is ‘ to hear, adjudge, and condemn.’ In so doing it is exercising the judicial function.

“ What the Senate is engaged in doing is not investigating the Attorney General’s office; it is investigating the former Attorney General. What it has done is to put him on trial before it. In so doing it is exercising the judicial function. This it has no power to do.”

We are of opinion that the court’s ruling on this question was wrong, and that it sufficiently appears, when the proceedings are rightly interpreted, that the object of the investigation and of the effort to secure the witness’s testimony was to obtain information for legislative purposes.

It is quite true that the resolution directing the investigation does not in terms avow that it is intended to be, in aid of legislation; but it does show that the subject to be investigated was the administration of the Department of Justice — whether its functions were being properly discharged or were being neglected or misdirected, and particularly whether the Attorney General and his assistants were performing or neglecting their duties in respect of the institution and prosecution of proceedings to punish crimes and enforce appropriate remedies against the-wrongdoers — specific instances of alleged neglect being' recited. Plainly the subject was one on which legislation' could be had and would be materially aided by the information which the investigation was calculated to elicit. ■ *178This becomes manifest when it is reflected that the functions of the Department of.Justice, the powers and duties of the' Attorney General and the duties of his assistants, are all subject to regulation by congressional legislation, and that the department is maintained and its activities are carried on under such appropriations as in the judgment of Congress are needed from year to year.

The only legitimate object the Senate could have in ordering the investigation was to aid it in legislating; and we think the subject-matter was such that the presumption süouidbe indulged that this was the real object. An express avowal oí tne object would have been'better; but in view of the particular subiect-matter was not indispensable.-, In the Chapman case, where the .resolution contained, no avowal, this Court pointed out that it plainly related to a subject-matter of which the Senate had jurisdiction, and said “We cannot assume on this record that the action of the Senate was without a legitimate object”; and also that “it was certainly not necessary that the resolutions should declare in advance what the Senate meditated doing when the investigation was concluded.” • (166 U. S. 669-670.) In People v. Keeler, 99 N. Y. 463, where the Court of Appeals of New York sustained an investigation ordered by the Senate of that state where the resolution contained no avowal, but disclosed that it definitely related to the. administration of a public office the duties of which were subject to legislative regulation, the court said (pp.485, 487) : “ Where public institutions under the control of the State are ordered to be investigated it is generally with .the view of some legislative action respecting them, and the -same may be said in respect of public officers.” And again: “Wé are bound to presume that the action of the legislative body was with a legitimate object if it is capable of being so construed, and we have no right to assume that the contrary was intended.”

*179While we rest our conclusion respecting the object of the investigation on the grounds just stated, it is well- to observe that this view of what was intended is not new, but was shown in the debate on the resolution.20

Of course, our. concern is with the substance of the resolution and not with any nice questions of propriety respecting its direct reference to the then Attorney General by name. The resolution, like the charges which prompted its adoption, related to the activities of the department while he was its supervising officer; and the reference to him by name served to designate the period to which the investigation was directed.

We think the resolution and proceedings give no warrant for thinking the Senate was attempting or intending to try' the Attorney General at its bar or before its committee for any crime or wrongdoing. Nor do we think *180it a valid objection to the investigation that it might possibly disclose crime or wrongdoing on his part.

The second resolution — the one directing that the witness be attached — declares that his testimony is sought with the purpose of obtaining “ information necessary as a basis for such legislative and other action as the Senate may deem necessary and proper.” This avowal of contemplated legislation is in accord with what we think is the right interpretation of the earlier resolution directing the investigation.' The suggested possibility of “ other action ” if deemed “ necessary or proper ” is of course open to criticism in that there is no other action in the matter which would be within the power of the Senate. But we do not assent to the view that this indefinite and untenable suggestion invalidates the entire proceeding. The right view in our opinion is that it takes nothing from the lawful object avowed in the same resolution and rightly inferable from the earlier one. It is not as if an inadmissible or unlawful object were affirmatively and definitely avowed.

We conclude that the investigation was ordered for a legitimate object; that the witness wrongfully refused to appear and testify before the committee and was lawfully attached; that the Senate is entitled to have him give testimony pertinent to the inquiry, either at its bar or before the committee; and that the district court erred, in discharging him from custody under the attachment.

Another question has arisen which should be noticed. It is whether the case has become moot. The investigation was ordered and the committee appointed during the Sixty-eighth Congress. That Congress expired March 4, 1925. The resolution ordering the investigation in terms limited the committee’s authority to the period of the Sixty-eighth Congress; but this apparently was changed by a later and amendatory resolution authorizing the committee to sit at such times and places as it might *181deem advisable or necessary.21 It is said in Jefferson’s Manual:22 “Neither House can continue any portion of itself in any parliamentary function beyond the end of the session without the consent of the other two branches. When done, it is by a bill constituting them commissioners for the particular purpose.” But the context shows that the reference is to the two houses of Parliament when adjourned by prorogation or dissolution by the King. The rule may be the same with the House of Representatives whose members are all elected for the period of a single Congress; but it cannot well be the same with the Senate, which is a continuing body whose members are elected for a term of six years and so divided, into classes that the seats of one-third only become vacant at the end of each Congress, two-thirds always continuing into the next Congress, save as vacancies may occur through death or resignation.

Mr. Hinds in his collection of precedents says: “The Senate, as a continuing body, may continue its committees through the recess following the expiration of a Congress”;23 and, after quoting the above statement from Jefferson’s Manual, he says: “The Senate, however, being a continuing body, gives authority to its committees during the recess after the expiration of a Congress.” 24 So far as we are advised the select committee having this investigation in charge has neither made a final report nor been discharged; nor has it been continued by an affirmative order. Apparently its activities have been suspended pending the decision of this case. But, be this as it may, it is certain that the committee may be continued or revived now by motion to that effect, and, if continued or revived, will have all its original powers.25 *182This being so, and the Senate being a continuing body, the case cannot be said to have become moot in the ordinary sense. The situation is measurably like that in Southern Pacific Terminal Co. v. Interstate Commerce Commission, 219 U. S. 498, 514-516, where it was held that a suit to enjoin the enforcement of an order of the Interstate Commerce Commission' did not become moot through the expiration of the order where it was capable of repetition by the commission and was a matter of public interest. Our judgment may yet be carried into effect and the investigation proceeded with from the point at which it apparently was interrupted by reason of the habeas corpus proceedings. In these' circumstances we think a judgment should be rendered as was done in. the case cited.

What has been said requires that the final order in the district court discharging the witness from custody be reversed.

Final order reversed.

Mr. Justice Stone did not'participate in the consideration or decision of the case.

1

Rev. Stats, secs. 346, 350, 359, 360, 361, 362, 367; Judicial Code, secs. 185, 212; c. 382, secs. 3, 5, 25 Stat. 858, 859; c. 647,’ sec. 4, 26 Stat. 209; c. 3935, 34 Stat. 816; c. 323, sec. 15, 38 Stat. 736; United States v. San Jacinto Tin Co., 125 U. S. 273, 278; Kern River Co. v. United States, 257 U. S. 147. 155; Ponzi v. Fessenden, 258 U. S. 254, 262.

2

Cong. Rec. 68th Cong., 1st Sess., pp. 1520, 1521, 1728; e. 16, 43 Stat, 5; Cong. Rec. 68th Cong., 1st Sess., pp. 1591, 1974; c. 39, 43 Stat. 15; c. 42, 43 Stat. 16.

3

For the full resolution and two amendments adopted shortly thereafter see Cong. Ree., 68th Cong., 1st Sess., pp. 3299, 3409-3410, 3548, 4126.

4

Senate Report No. 475, 68th Cong., 1st Sess.

5

Cong. Reo., 68th Cong., 1st Sess., pp. 7215-7217.

6

Senate Journal 47, 51-1, Dec. 17, 1889; Senate Rules and Manual, 68th Cong., p. 114.

7

41 Stat. 632, 1253 ; 42 Stat. 424, 1266; 43 Stat. 33, 580, 1288.

8

Prigg v. Pennsylvania, 16 Pet. 539, 620-621; The Laura, 114 U. 3. 411, 416;- McPherson v. Blacker, 146 U. S. 1, 35-36; Ex parte Grossman, 267 U. S. 87, 118; Myers v. United States, 272 U. S. 52.

9

Ex parte Terry, 128 U. S. 289, 307, et seq.; Holcomb v. Cornish, 8 Conn. 375; 4 Blackst. Com. 286.

10

Robbins v. Gorham, 25 N. Y. 588; Wilson v. State, 57 Ind. 71.

11

Hale v. Henkel, 201 U. S. 43, 60-62; Regina v. Russell, 2 Car. & Mar. 247; Commonwealth v. Hayden, 163 Mass. 453, 455; Decision of Mr. Justice Catron reported in Wharton’s Cr. Pl. & Pr., 8th ed., pp. 224-226,

12

See Hale v. Henkel, supra; Blair v. United States, 250 U. S. 273; Nelson v. United States, 201 U. S. 92, 95; Equity Rule 52, 226 U. S. Appendix, 15; Heard v. Pierce, 8 Cush. 338.

13

“ On the ilth day of April, 1924, in an action in the Court of Common Pleas of said Fayette County, Ohio, in which said The Midland National Bank was plaintiff and said B. K. Wheeler and Smith W. Brookhart were defendants, upon the petition of said bank said court granted a temporary restraining order enjoining and restraining said defendants and their agents, servants, and employees from entering into said banking room and from taking, examining, or investigating any of the books, accounts, records, promissory notes, securities, letters, correspondence, papers, or any other property of said bank or of its depositors, borrowers, or customers in said banking room and from in any manner molesting and interfering with the business -and affairs of said bank, its officers, agents, servants, and the business of its depositors, borrowers and customers with said bank until the further order of said court. The said defendants were duly served with process in said action and duly served with copies of said temporary restraining order on said 11th day of April,’ 1924, and said injunction has not been modified by said court and no further order has been made in said case by said court, and said injunction is in full force and effect.”

14

Story Const., secs. 545, et seq.; 1 Kent’s Com., p. 222.

15

May’s Parliamentary Practice, 2d ed., pp. 80, 295, 299; Cushing’s Legislative Practice, secs. 634, 1901-1^03; 3 Hinds’ Precedents, secs. 1722, 1725, 1727, 1813-1820; Cooley’s Constitutional Limitations, 6th ed., p. 161.

16

The reference is to the power of the particular house to deal with the contempt, In re Chapman, 166 U. S. 661, 671-672.

17

In construing section 1 of the Act of 1857 as reproduced in section 102, of the Revised Statutes, this Court said in In re Chapman, 166 U. S. 661, 667:

“ It is true that the reference is to ' any ’ matter under inquiry, and so on, and it is suggested that this is fatally defective because too broad and unlimited in its extent; but nothing is better settled than that statutes should receive a sensible construction, such as will effectuate the legislative intention, and, if possible, so as to avoid an unjust or an absurd conclusion, Lau Ow Bew v. United States, 144 U. S. 47, 59; and we think that the word 1 any,’ as used in these sections, refers to matters within the jurisdiction of the two Houses of Congress, before them for consideration and proper for their action; to questions pertinent thereto; and to fapts or papers bearing thereon.”

18

This Court has said of the act of 1857 that “ it was necessary and proper for carrying into execution the powers vested in Congress and in each house thereof,” In re Chapman, 166 U. S. 661, 671,

19

Stuart v. Laird, 1 Cranch 299, 309; Martin v. Hunter’s Lessee, 1 Wheat. 304, 351; Ames v. Kansas, 111 U. S. 449, 469; Knowlton v. Moore, 178 U. S, 41, 56, 92; Fairbank v. United States, 181 U. S. 283, 306, et seq.

20

Senator George said: “ It is not a trial now that is proposed, and there has been no trial proposed save the civil and criminal actions to be instituted and prosecuted by counsel employed under the resolution giving to the President the power to employ counsel. We are not to try the Attorney General. He is not to go upon trial. Shall we say the legislative branch of the Government shall stickle and halt and hesitate because a man’s public reputation, his public character, may suffer because of that legislative action? Has not the Senate power to appoint a committee to investigate any department of the Government, any department supported by the Senate in part by appropriations made by the Congress? If the Senate has the right to investigate the department, is the Senate to-hesitate, is the Senate to refuse to do its duty merely because the public character or the public reputation of some one who is investigated may be thereby smirched, to use the term that has been used so often in the debate? . It is sufficient for me to know that there are grounds upon which I may justly base my vote for the resolution; and I am willing to leave it to the agent created by the Senate to proceed with the investigation fearlessly upon principle, not for the purpose of trying but for the purpose of ascertaining facts which the Senate is entitled to have within its possession in order that it may properly function as -a legislative body.” Cong, flee., 68th Cong., 1st Sess., pp. 3397, 3398.

21

Cong. Rec., 68th Cong., 1st Sess., p. 4126.

22

Senate Rules and Manual, 1925, p. 303.

23

Vol. 4, sec. 4544.

24

Vol. 4, sec 4545.

25

Hinds’ Precedents, Vol. 4, secs. 4396, 4400, 4404, 4405.

WATKINS v. UNITED STATES.

No. 261.

Argued March 7, 1957.

Decided June 17, 1957.

*181Joseph L. Rauh, Jr. argued the cause for petitioner. With him on the brief were Harold A. Cranefield, Norma Zarky, John Silard, Daniel H. Pollitt and Sidney S. Sachs.

Solicitor General Rankin argued the cause for the United States. With him on the brief were Assistant Attorney General Tompkins, Philip R. Monahan and Doris H. Spangenburg.

Osmond K. Fraenkel filed a brief for the American Civil Liberties Union, as amicus curiae, supporting petitioner, and Telford Taylor filed a brief for Metcalf, as amicus curiae, urging reversal.

Herbert R. O’Conor filed a brief for the American Bar Association, as amicus curiae, urging affirmance. With him on the brief were Julius Applebaum, Tracy E. Griffin, John M. Palmer, Paul W. Updegraff and Louis C. Wyman.

Me. Chief Justice Warren

delivered the opinion of the Court.

This is a review by certiorari of a conviction under 2 U. S. C. § 192 for “contempt of Congress.” The misdemeanor is alleged to have been committed during a *182hearing before a congressional investigating committee. It is not the case of a truculent or contumacious witness who refuses to answer all questions or who, by boisterous or discourteous conduct, disturbs the decorum of the committee room. Petitioner was prosecuted for refusing to make certain disclosures which he asserted to be beyond the authority of the committee to demand. The controversy thus rests upon fundamental principles of the power of the Congress and the limitations upon that power. We approach the questions presented with conscious awareness of the far-reaching ramifications that can follow from a decision of this nature.

On April 29, 1954, petitioner appeared as a witness in compliance with a subpoena issued by a Subcommittee of the Committee on Un-American Activities of the House of Representatives. The Subcommittee elicited from petitioner a description of his background in labor union activities. He had been an employee of the International Harvester Company between 1935 and 1953. During the last eleven of those years, he had been on leave of absence to serve as an official of the Farm Equipment Workers International Union, later merged into the United Electrical, Radio and Machine Workers. He rose to the position of President of District No. 2 of the Farm Equipment Workers, a district defined geographically to include generally Canton and Rock Falls, Illinois, and Dubuque, Iowa. In 1953, petitioner joined the United Automobile Workers International Union as a labor organizer.

Petitioner’s name had been mentioned by two witnesses who testified before the Committee at prior hearings. In September 1952, one Donald 0. Spencer admitted having been a Communist from 1943 to 1946. He declared that he had been recruited into the Party with the endorsement and prior approval of petitioner, whom he identified as the then District Vice-President of the Farm Equip*183ment Workers.1 Spencer also mentioned that petitioner had attended meetings at which only card-carrying Communists were admitted. A month before petitioner testified, one Walter Rumsey stated that he had been recruited into the Party by petitioner.2 Rumsey added that he had paid Party dues to, and later collected dues from, petitioner, who had assumed the name, Sam Brown. Rum-sey told the Committee that he left the Party in 1944.

Petitioner answered these allegations freely and without reservation. His attitude toward the inquiry is clearly revealed from the statement he made when the questioning turned to the subject of his past conduct, associations and predilections:

“I am not now nor have I ever been a card-carrying member of the Communist Party. Rumsey was wrong when he said I had recruited him into the party, that I had received his dues, that I paid dues to him, and that I had used the alias Sam Brown.

“Spencer was wrong when he termed any meetings which I attended as closed Communist Party meetings.

“I would like to make it clear that for a period of time from approximately 1942 to 1947 I cooperated with the Communist Party and participated in Communist activities to such a degree that some persons may honestly believe that I was a member of the party.

“I have made contributions upon occasions to Communist causes. I have signed petitions for Commu*184nist causes. I attended caucuses at an FE convention at which Communist Party officials were present.

“Since I freely cooperated with the Communist Party I have no motive for making the distinction between cooperation and membership except the simple fact that it is the truth. I never carried a Communist Party card. I never accepted discipline and indeed on several occasions I opposed their position.

“In a special convention held in the summer of 1947 I led the fight for compliance with the Taft-Hartley Act by the FE-CIO International Union. This fight became so bitter that it ended any possibility of future cooperation.” 3

The character of petitioner’s testimony on these matters can perhaps best be summarized by the Government’s own appraisal in its brief:

“A more complete and candid statement of his past political associations and activities (treating the Communist Party for present purposes as a mere political party) can hardly be imagined. Petitioner certainly was not attempting to conceal or withhold from the Committee his own past political associations, predilections, and preferences. Furthermore, petitioner told the Committee that he was entirely willing to identify for the Committee, and answer any questions it might have concerning, ‘those persons whom I knew to be members of the Communist Party,’ provided that, ‘to [his] best knowledge and belief,’ they still were members of the Party . . . .”4

The Subcommittee, too, was apparently satisfied with petitioner’s disclosures. After some further discussion elaborating on the statement, counsel for the Committee *185turned to another aspect of Rumsey’s testimony. Rum-sey had identified a group of persons whom he had known as members of the Communist Party, and counsel began to read this list of names to petitioner. Petitioner stated that he did not know several of the persons. Of those whom he did know, he refused to tell whether he knew them to have been members of the Communist Party. He explained to the Subcommittee why he took such a position:

“I am not going to plead the fifth amendment, but I refuse to answer certain questions that I believe are outside the proper scope of your committees activities. I will answer any questions which this committee puts to me about myself. I will also answer questions about those persons whom I knew to be members of the Communist Party and whom I believe still are. I will not, however, answer any questions with respect to others with whom I associated in the past. I do not believe that any law in this country requires me to testify about persons who may in the past have been Communist Party members or otherwise engaged in Communist Party activity but who to my best knowledge and belief have long since removed themselves from the Communist movement.

“I do not believe that such questions are relevant to the work of this committee nor do I believe that this committee has the right to undertake the public exposure of persons because of their past activities. I may be wrong, and the committee may have this power, but until and unless a court of law so holds and directs me to answer, I most firmly refuse to discuss the political activities of my past associates.” 5

*186The Chairman of the Committee submitted a report of petitioner’s refusal to answer questions to the House of Representatives. H. R. Rep. No. 1579, 83d Cong., 2d Sess. The House directed the Speaker to certify the Committee’s report to the United States Attorney for initiation of criminal prosecution. H. Res. 534, 83d Cong., 2d Sess.6 A seven-count indictment was returned.7 Petitioner waived his right to jury trial and was found guilty on all counts by the court. The sentence, a fine of $100 and one year in prison, was suspended, and petitioner was placed on probation.

An appeal was taken to the Court of Appeals for the District of Columbia. The conviction was reversed by a three-judge panel, one member dissenting. Upon rehearing en banc, the full bench affirmed the conviction with the judges of the original majority in dissent. 98 U. S. App. D. C. 190, 233 F. 2d 681. We granted certio-*187rari because of the very important questions of constitutional law presented. 352 U. S. 822.

We start with several basic premises on which there is general agreement. The power of the Congress to conduct investigations is inherent in the legislative process. That power is broad. It encompasses inquiries concerning the administration of existing laws as well as proposed or possibly needed statutes. It includes surveys of defects in our social, economic or political system for the purpose of enabling the Congress to remedy them. It comprehends probes into departments of the Federal Government to expose corruption, inefficiency or waste. But, broad as is this power of inquiry, it is not unlimited. There is no general authority to expose the private affairs of individuals without justification in terms of the functions of the Congress. This was freely conceded by the Solicitor General in his argument of this case.8 Nor is the Congress a law enforcement or trial agency. These are functions of the executive and judicial departments of government. No inquiry is an end in itself; it must be related to, and in furtherance of, a legitimate task of the Congress. Investigations conducted solely for the personal aggrandizement of the investigators or to “punish” those investigated are indefensible.

It is unquestionably the duty of all citizens to cooperate with the Congress in its efforts to obtain the facts needed for intelligent legislative action. It is their unremitting obligation to respond to subpoenas, to respect the dignity of the Congress and its committees and to testify *188fully with respect to matters within the province of proper investigation. This, of course, assumes that the constitutional rights of witnesses will be respected by the Congress as they are in a court of justice. The Bill of Rights is applicable to investigations as to all forms of governmental action. Witnesses cannot be compelled to give evidence against themselves. They cannot be subjected to unreasonable search and seizure. Nor can the First Amendment freedoms of speech, press, religion, or political belief and association be abridged.

The rudiments of the power to punish for “contempt of Congress” come to us from the pages of English history. The origin of privileges and contempts extends back into the period of the emergence of Parliament. The establishment of a legislative body which could challenge the absolute power of the monarch is a long and bitter story. In that struggle, Parliament made broad and varied use of the contempt power. Almost from the beginning, both the House of Commons and the House of Lords claimed absolute and plenary authority over their privileges. This was an independent body of law, described by Coke as lex parliamenti.9 Only Parliament could declare what those privileges were or what new privileges were occasioned, and only Parliament could judge what conduct constituted a breach of privilege.

In particular, this exclusion of lex parliamenti from the lex terrae, or law of the land, precluded judicial review of the exercise of the contempt power or the assertion of privilege. Parliament declared that no court had jurisdiction to consider such questions. In the latter part of the seventeenth century, an action for false imprisonment was brought by one Jay who had been held in contempt. The defendant, the Ser jeant-at-Arms of the House of Commons, demurred that he had taken the plaintiff *189into custody for breach of privilege. The Chief Justice, Pemberton, overruled the demurrer. Summoned to the bar of the House, the Chief Justice explained that he believed that the assertion of privilege went to the merits of the action and did not preclude jurisdiction. For his audacity, the Chief Justice was dispatched to Newgate Prison.10

It seems inevitable that the power claimed by Parliament would have been abused. Unquestionably it was. A few examples illustrate the way in which individual rights were infringed. During the seventeenth century, there was a violent upheaval, both religious and political. This was the time of the Reformation and the establishment of the Church of England. It was also the period when the Stuarts proclaimed that the royal prerogative was absolute. Ultimately there were two revolutions, one protracted and bloody, the second without bloodshed. Critical commentary of all kinds was treated as contempt of Parliament in these troubled days. Even clergymen were imprisoned for remarks made in their sermons.11 Perhaps the outstanding case arose from the private conversation of one Floyd, a Catholic, in which he expressed pleasure over the misfortune of the King's Protestant son-in-law and his wife. Floyd was not a member of Parliament. None of the persons concerned was in any way connected with the House of Commons. Nevertheless, that body imposed an humiliating and cruel sentence upon Floyd for contempt.12 The House of Lords inter*190vened, rebuking the Commons for their extension of the privilege. The Commons acceded and transferred the record of the case to the Lords, who imposed substantially the same penalty.13

Later in that century, during the reign of Charles II, there was great unrest over the fact that the heir apparent, James, had embraced Catholicism. Anti-Catholic feeling ran high, spilling over a few years later when the infamous rogue, Titus Oates, inflamed the country with rumors of a “Popish Plot” to murder the King. A committee of Parliament was appointed to learn the sources of certain pamphlets that had been appearing. One was entitled: The Grand Question Concerning the Prorogation of this Parliament for a Year and Three Months Stated and Discussed. A Doctor Carey admitted to the committee that he knew the author, but refused to divulge his name. Brought to the bar of the House of Lords, he persisted in this stand. The House imposed a fine of £1,000 and committed the witness to the Tower.14

A hundred years later, George III had managed to gain control of Parliament through his ministers. The King could not silence the opposition, however, and one of the most vocal was John Wilkes. This precipitated a *191struggle that lasted for several years until Wilkes finally prevailed. One writer sums up the ease thus:

“He had won a victory for freedom of the press. He had directed popular attention to the royally-controlled House of Commons, and pointed out its unrepresentative character, and had shown how easily a claim of privilege might be used to sanction the arbitrary proceedings of ministers and Parliament, even when a fundamental right of the subject was concerned. It was one of life’s little ironies that work of such magnitude had been reserved for one of the worst libertines and demagogues of all time.”15

Even as late as 1835, the House of Commons appointed a select committee to inquire into “. . . the origin, nature, extent and tendency of the Orange Institutions.” This was a political-religious organization, vehemently Protestant in religion and strongly in favor of the growth of the British Empire. The committee summoned the Deputy Grand Secretary and demanded that he produce all the records of the organization. The witness refused to turn over a letter-book, which he admitted contained his answers to many communications upon Orange business. But it also contained, he said, records of private communications with respect to Orangeism. Summoned to the bar of the House of Commons, he remained adamant and was committed to Newgate Prison.16

Modern times have seen a remarkable restraint in the use by Parliament of its contempt power. Important investigations, like those conducted in America by congressional committees, are made by Royal Commissions *192of Inquiry.17 These commissions are comprised of experts in the problem to be studied. They are removed from the turbulent forces of politics and partisan considerations. Seldom, if ever, have these commissions been given the authority to compel the testimony of witnesses or the production of documents.18 Their success in fulfilling their fact-finding missions without resort to coercive tactics is a tribute to the fairness of the processes to the witnesses and their close adherence to the subject matter committed to them.

The history of contempt of the legislature in this country is notably different from that of England. In the early days of the United States, there lingered the direct knowledge of the evil effects of absolute power. Most of the instances of use of compulsory process by the first Congresses concerned matters affecting the qualification or integrity of their members or came about in inquiries dealing with suspected corruption or mismanagement of government officials.19 Unlike the English practice, from the very outset the use of contempt power by the legislature was deemed subject to judicial review.20

There was very little use of the power of compulsory process in early years to enable the Congress to obtain facts pertinent to the enactment of new statutes or the *193administration of existing laws. The first occasion for such an investigation arose in 1827 when the House of Representatives was considering a revision of the tariff laws.21 In the Senate, there was no use of a fact-finding investigation in aid of legislation until 1859.22 In the Legislative Reorganization Act, the Committee on Un-American Activities was the only standing committee of the House of Representatives that was given the power to compel disclosures.23

It is not surprising, from the fact that the Houses of Congress so sparingly employed the power to conduct investigations, that there have been few cases requiring judicial review of the power. The Nation was almost one hundred years old before the first case reached this Court to challenge the use of compulsory process as a legislative device, rather than in inquiries concerning the elections *194or privileges of Congressmen.24 In Kilbourn v. Thompson, 103 U. S. 168, decided in 1881, an investigation had been authorized by the House of Representatives to learn the circumstances surrounding the bankruptcy of Jay Cooke & Company, in which the United States had deposited funds. The committee became particularly interested in a private real estate pool that was a part of the financial structure. The Court found that the subject matter of the inquiry was “in its nature clearly judicial and therefore one in respect to which no valid legislation could be enacted.” The House had thereby exceeded the limits of its own authority.

Subsequent to the decision in Kilbourn, until recent times, there were very few cases dealing with the investigative power.25 The matter came to the fore again when the Senate undertook to study the corruption in the handling of oil leases in the 1920’s. In McGrain v. Daugherty, 273 U. S. 135, and Sinclair v. United States, 279 U. S. 263, the Court applied the precepts of Kilbourn to uphold the authority of the Congress to conduct the challenged investigations. The Court recognized the danger to effective and honest conduct of the Government *195if the legislature’s power to probe corruption in the executive branch were unduly hampered.

Following these important decisions, there was another lull in judicial review of investigations. The absence of challenge, however, was not indicative of the absence of inquiries. To the contrary, there was vigorous use of the investigative process by a Congress bent upon harnessing and directing the vast economic and social forces of the times. Only one case came before this Court, and the authority of the Congress was affirmed.26

In the decade following World War II, there appeared a new kind of congressional inquiry unknown in prior periods of American history. Principally this was the result of the various investigations into the threat of subversion of the United States Government, but other subjects of congressional interest also contributed to the changed scene. This new phase of legislative inquiry involved a broad-scale intrusion into the lives and affairs of private citizens. It brought before the courts novel questions of the appropriate limits of congressional inquiry. Prior cases, like Kilbourn, McGrain and Sinclair, had defined the scope of investigative power in terms of the inherent limitations of the sources of that power. In the more recent cases, the emphasis shifted to problems of accommodating the interest of the Government with the rights and privileges of individuals. The central theme was the application of the Bill of Rights as a restraint upon the assertion of governmental power in this form.

It was during this period that the Fifth Amendment privilege against self-incrimination was frequently in*196voked and recognized as a legal limit upon the authority of a committee to require that a witness answer its questions.27 Some early doubts as to the applicability of that privilege before a legislative committee never matured.28 When the matter reached this Court, the Government did not challenge in any way that the Fifth Amendment protection was available to the witness, and such a challenge could not have prevailed. It confined its argument to the character of the answers sought and to the adequacy of the claim of privilege. Quinn v. United States, 349 U. S. 155; Emspak v. United States, 349 U. S. 190; Bart v. United States, 349 U. S. 219.29

A far more difficult task evolved from the claim by witnesses that the committees’ interrogations were infringements upon the freedoms of the First Amendment.30 *197Clearly, an investigation is subject to the command that the Congress shall make no law abridging freedom of speech or press or assembly. While it is true that there is no statute to be reviewed, and that an investigation is not a law, nevertheless an investigation is part of lawmaking. It is justified solely as an adjunct to the legislative process. The First Amendment may be invoked against infringement of the protected freedoms by law or by lawmaking.31

Abuses of the investigative process may imperceptibly lead to abridgment of protected freedoms. The mere summoning of a witness and compelling him to testify, against his will, about his beliefs, expressions or associations is a measure of governmental interference. And when those forced revelations concern matters that are unorthodox, unpopular, or even hateful to the general public, the reaction in the life of the witness may be disastrous. This effect is even more harsh when it is past beliefs, expressions or associations that are disclosed and judged by current standards rather than those contemporary with the matters exposed. Nor does the witness alone suffer the consequences. . Those who are identified by witnesses and thereby placed in the same glare of publicity are equally subject to public stigma, scorn and obloquy. Beyond that, there is the more subtle and immeasurable effect upon those who tend to adhere to *198the most orthodox and uncontroversial views and associations in order to avoid a similar fate at some future time. That this impact is partly the result of non-governmental activity by private persons cannot relieve the investigators of their responsibility for initiating the reaction.

The Court recognized the restraints of the Bill of Rights upon congressional investigations in United States v. Rumely, 345 U. S. 41. The magnitude and complexity of the problem of applying the First Amendment to that case led the Court to construe narrowly the resolution describing the committee’s authority. It was concluded that, when First Amendment rights are threatened, the delegation of power to the committee must be clearly revealed in its charter.

Accommodation of the congressional need for particular information with the individual and personal interest in privacy is an arduous and delicate task for any court. We do not underestimate the difficulties that would attend such an undertaking. It is manifest that despite the adverse effects which follow upon compelled disclosure of private matters, not all such inquiries are barred. Kilbourn v. Thompson teaches that such an investigation into individual affairs is invalid if unrelated to any legislative purpose. That is beyond the powers conferred upon the Congress in the Constitution. United States v. Rumely makes it plain that the mere semblance of legislative purpose would not justify an inquiry in the face of the Bill of Rights. The critical element is the existence of, and the weight to be ascribed to, the interest of the Congress in demanding disclosures from an unwilling witness. We cannot simply assume, however, that every congressional investigation is justified by a public need that overbalances any private rights affected. To do so would be to abdicate the responsibility placed by the Constitution upon the judiciary to insure that the Congress does not unjustifiably encroach upon an individual’s *199right to privacy nor abridge his liberty of speech, press, religion or assembly.

Petitioner has earnestly suggested that the difficult questions of protecting these rights from infringement by legislative inquiries can be surmounted in this case because there was no public purpose served in his interrogation. His conclusion is based upon the thesis that the Subcommittee was engaged in a program of exposure for the sake of exposure. The sole purpose of the inquiry, he contends, was to bring down upon himself and others the violence of public reaction because of their past beliefs, expressions and associations. In support of this argument, petitioner has marshalled an impressive array of evidence that some Congressmen have believed that such was their duty, or part of it.32

*200We have no doubt that there is no congressional power to expose for the sake of exposure. The public is, of course, entitled to be informed concerning the workings of its government.33 That cannot be inflated into a general power to expose where the predominant result can only be an invasion of the private rights of individuals. But a solution to our problem is not to be found in testing the motives of committee members for this purpose. Such is not our function. Their motives alone would not vitiate an investigation which had been instituted by a House of Congress if that assembly’s legislative purpose is being served.34

Petitioner’s contentions do point to a situation of particular significance from the standpoint óf the constitutional limitations upon congressional investigations. The theory of a committee inquiry is that the committee members are serving as the representatives of the parent assembly in collecting information for a legislative purpose. Their function is to act as the eyes and ears of the Congress in obtaining facts upon which the full legislature can act. To carry out this mission, committees and subcommittees, sometimes one Congressman, *201are endowed with the full power of the Congress to compel testimony. In this case, only two men exercised that authority in demanding information over petitioner’s protest.

An essential premise in this situation is that the House or Senate shall have instructed the committee members on what they are to do with the power delegated to them. It is the responsibility of the Congress, in the first instance, to insure that compulsory process is used only in furtherance of a legislative purpose. That requires that the instructions to an investigating committee spell out that group’s jurisdiction and purpose with sufficient particularity. Those instructions are embodied in the authorizing resolution. That document is the committee’s charter. Broadly drafted and loosely worded, however, such resolutions can leave tremendous latitude to the discretion of the investigators. The more vague the committee’s charter is, the greater becomes the possibility that the committee’s specific actions are not in conformity with the will of the parent House of Congress.

The authorizing resolution of the Un-American Activities Committee was adopted in 1938 when a select committee, under the chairmanship of Representative Dies, was created.35 Several years later, the Committee was made a standing organ of the House with the same mandate.36 It defines the Committee’s authority as follows:

“The Committee on Un-American Activities, as a whole or by subcommittee, is authorized to make from time to time investigations of (1) the extent, character, and objects of un-American propaganda activities in the United States, (2) the diffusion *202within the United States of subversive and un-Amer-ican propaganda that is instigated from foreign countries or of a domestic origin and attacks the principle of the form of government as guaranteed by our Constitution, and (3) all other questions in relation thereto that would aid Congress in any necessary remedial legislation.” 37

It would be difficult to imagine a less explicit authorizing resolution. Who can define the meaning of “un-American”? What is that single, solitary “principle of the form of government as guaranteed by our Constitution”? 38 There is no need to dwell upon the language, however. At one time, perhaps, the resolution might have been read narrowly to confine the Committee to the subject of propaganda.39 The events that have transpired in the fifteen years before the interrogation of petitioner make such a construction impossible at this date.

The members of the Committee have clearly demonstrated that they did not feel themselves restricted in any way to propaganda in the narrow sense of the word.40 *203Unquestionably the Committee conceived of its task in the grand view of its name. Un-American activities were its target, no matter how or where manifested. Notwithstanding the broad purview of the Committee’s experience, the House of Representatives repeatedly approved its continuation. Five times it extended the life of the special committee.41 Then it made the group a standing committee of the House.42 A year later, the Committee’s charter was embodied in the Legislative Reorganization Act.43 On five occasions, at the beginning of sessions of Congress, it has made the authorizing resolution part of the rules of the House.44 On innumerable occasions, it has passed appropriation bills to allow the Committee to continue its efforts.

Combining the language of the resolution with the construction it has been given, it is evident that the preliminary control of the Committee exercised by the House *204of Representatives is slight or non-existent. No one could reasonably deduce from the charter the kind of investigation that the Committee was directed to make. As a result, we are asked to engage in a process of retroactive rationalization. Looking backward from the events that transpired, we are asked to uphold the Committee’s actions unless it appears that they were clearly not authorized by the charter. As a corollary to this inverse approach, the Government urges that we must view the matter hospitably to the power of the Congress — that if there is any legislative purpose which might have been furthered by the kind of disclosure sought, the witness must be punished for withholding it. No doubt every reasonable indulgence of legality must be accorded to the actions of a coordinate branch of our Government. But such deference cannot yield to an unnecessary and unreasonable dissipation of precious constitutional freedoms.

The Government contends that the public interest at the core of the investigations of the Un-American Activities Committee is the need by the Congress to be informed of efforts to overthrow the Government by force and violence so that adequate legislative safeguards can be erected. From this core, however, the Committee can radiate outward infinitely to any topic thought to be related in some way to armed insurrection. The outer reaches of this domain are known only by the content of “un-American activities.” Remoteness of subject can be aggravated by a probe for a depth of detail even farther removed from any basis of legislative action. A third dimension is added when the investigators turn their attention to the past to collect minutiae on remote topics, on the hypothesis that the past may reflect upon the present.

The consequences that flow from this situation are manifold. In the first place, a reviewing court is unable *205to make the kind of judgment made by the Court in United States v. Rumely, supra. The Committee is allowed, in essence, to define its own authority, to choose the direction and focus of its activities. In deciding what to do with the power that has been conferred upon them, members of the Committee may act pursuant to motives that seem to them to be the highest. Their decisions, nevertheless, can lead to ruthless exposure of private lives in order to gather data that is neither desired by the Congress nor useful to it. Yet it is impossible in this circumstance, with constitutional freedoms in jeopardy, to declare that the Committee has ranged beyond the area committed to it by its parent assembly because the boundaries are so nebulous.

More important and more fundamental than that, however, it insulates the House that has authorized the investigation from the witnesses who are subjected to the sanctions of compulsory process. There is a wide gulf between the responsibility for the use of investigative power and the actual exercise of that power. This is an especially vital consideration in assuring respect for constitutional liberties. Protected freedoms should not be placed in danger in the absence of a clear determination by the House or the Senate that a particular inquiry is justified by a specific legislative need.

It is, of course, not the function of this Court to prescribe rigid rules for the Congress to follow in drafting resolutions establishing investigating committees. That is a matter peculiarly within the realm of the legislature, and its decisions will be accepted by the courts up to the point where their own duty to enforce the constitutionally protected rights of individuals is affected. An excessively broad charter, like that of the House Un-American Activities Committee, places the courts in an untenable position if they are to strike a balance between the public need for a particular interrogation and the right of *206citizens to carry on their affairs free from unnecessary governmental interference. It is impossible in such a situation to ascertain whether any legislative purpose justifies the disclosures sought and, if so, the importance of that information to the Congress in furtherance of its legislative function. The reason no court can make this critical judgment is that the House of Representatives itself has never made it. Only the legislative assembly initiating an investigation can assay the relative necessity of specific disclosures.

Absence of the qualitative consideration of petitioner’s questioning by the House of Representatives aggravates a serious problem, revealed in this case, in the relationship of congressional investigating committees and the witnesses who appear before them. Plainly these committees are restricted"* to the missions delegated to them, i. e., to acquire certain data to be used by the House or the Senate in coping with a problem that falls within its legislative sphere. No witness can be compelled to make disclosures on matters outside that area. This is a jurisdictional concept of pertinency drawn from the nature of a congressional committee’s source of authority. It is not wholly different from nor unrelated to the element of pertinency embodied in the criminal statute under which petitioner was prosecuted. When the definition of jurisdictional pertinency is as uncertain and wavering as in the case of the Un-American Activities Committee, it becomes extremely difficult for the Committee to limit its inquiries to statutory pertinency.

Since World War II, the Congress has practically abandoned its original practice of utilizing the coercive sanction of contempt proceedings at the bar of the House. The sanction there imposed is imprisonment by the House until the recalcitrant witness agrees to testify or disclose the matters sought, provided that the incarceration does *207not extend beyond adjournment. The Congress has instead invoked the aid of the federal judicial system in protecting itself against contumacious conduct. It has become customary to refer these matters to the United States Attorneys for prosecution under criminal law.

The appropriate statute is found in 2 U. S. C. § 192. It provides:

“Every person who having been summoned as a witness by the authority of either House of Congress to give testimony or to produce papers upon any matter under inquiry before either House, or any joint committee established by a joint or concurrent resolution of the two Houses of Congress, or any committee of either House of Congress, willfully makes default, or who, having appeared, refuses to answer any question pertinent to the question under inquiry, shall be deemed guilty of a misdemeanor., punishable by a fine of not more than $1,000 nor less than $100 and imprisonment in a common jail for not less than one month nor more than twelve months.”45

*208In fulfillment of their obligation under this statute, the courts must accord to the defendants every right which is guaranteed to defendants in all other' criminal cases. Among these is the right to have available, through a sufficiently precise statute, information revealing the standard of criminality before the commission of the alleged offense.46 Applied to persons prosecuted under § 192, this raises a special problem in that the statute defines the crime as refusal to answer “any question pertinent to the question under inquiry.” Part of the standard of criminality, therefore, is the pertinency of the questions propounded to the witness.47

The problem attains proportion when viewed from the standpoint of the witness who appears before a congressional committee. He must decide at the time the questions are propounded whether or not to answer. As the Court said in Sinclair v. United States, 279 U. S. 263, the witness acts at his peril. He is “. . . bound rightly to construe the statute.” Id., at 299. An erroneous determination on his part, even if made in the utmost good faith, does not exculpate him if the court should later rule that the questions were pertinent to the question under inquiry.

It is obvious that a person compelled to make this choice is entitled to have knowledge of the subject to *209which the interrogation is deemed pertinent. That knowledge must be available with the same degree of explicitness and clarity that the Due Process Clause requires in the expression of any element of a criminal offense. The "vice of vagueness” 48 must be avoided here as in all other crimes. There are several sources that can outline the “question under inquiry” in such a way that the rules against vagueness are satisfied. The authorizing resolution, the remarks of the chairman or members of the committee, or even the nature of the proceedings themselves, might sometimes make the topic clear. This case demonstrates, however, that these sources often leave the matter in grave doubt.

The first possibility is that the authorizing resolution itself will so clearly declare the “question under inquiry” that a witness can understand the pertinency of questions asked him. The Government does not contend that the authorizing resolution of the Un-American Activities Committee could serve such a purpose. Its confusing breadth is amply illustrated by the innumerable and diverse questions into which the Committee has inquired under this charter since 1938. If the “question under inquiry” were stated with such sweeping and uncertain scope, we doubt that it would withstand an attack on the ground of vagueness.

That issue is not before us, however, in light of the Government’s position that' the immediate subject under inquiry before the Subcommittee interviewing petitioner was only one aspect of the Committee’s authority to investigate un-American activities. Distilling that single topic from the broad field is an extremely difficult task upon the record before us. There was an opening statement by the Committee Chairman at the outset of the *210hearing, but this gives us no guidance. In this statement, the Chairman did no more than paraphrase the authorizing resolution and give a very general sketch of the past efforts of the Committee.49

*211No aid is given as to the “question under inquiry” in the action of the full Committee that authorized the creation of the Subcommittee before which petitioner appeared. The Committee adopted a formal resolution giving the Chairman the power to appoint subcommittees “. . . for the purpose of performing any and all acts which the Committee as a whole is authorized to do.” 50 In effect, this was a device to enable the investigations to proceed with a quorum of one or two members and *212sheds no light on the relevancy of the questions asked of petitioner.51

The Government believes that the topic of inquiry before the Subcommittee concerned Communist infiltration in labor. In his introductory remarks, the Chairman made reference to a bill, then pending before the Committee,52 which would have penalized labor unions controlled or dominated by persons who were, or had been, members of a “Communist-action” organization, as de*213fined in the Internal Security Act of 1950. The Subcommittee, it is contended, might have been endeavoring to determine the extent of such a problem.

This view is corroborated somewhat by the witnesses who preceded and followed petitioner before the Subcommittee. Looking at the entire hearings, however, there is strong reason to doubt that the subject revolved about labor matters. The published transcript is entitled: Investigation of Communist Activities in the Chicago Area, and six of the nine witnesses had no connection with labor at all.53

The most serious doubts as to the Subcommittee’s “question under inquiry,” however, stem from the precise questions that petitioner has been charged with refusing to answer. Under the terms of the statute, after all, it is these which must be proved pertinent. Petitioner is charged with refusing to tell the Subcommittee whether or not he knew that certain named persons had been members of the Communist Party in the past. The Subcommittee’s counsel read the list from the testimony of a previous witness who had identified them as Communists. Although this former witness was identified with labor, he had not stated that the persons he named were involved in union affairs. Of the thirty names propounded to petitioner, seven were completely unconnected with organized labor. One operated a beauty parlor. Another was a watchmaker. Several were identified as “just citizens” or “only Communists.” When *214almost a quarter of the persons on the list are not labor people, the inference becomes strong that the subject before the Subcommittee was not defined in terms of Communism in labor.

The final source of evidence as to the “question under inquiry” is the Chairman's response when petitioner objected to the questions on the grounds of lack of perti-nency. The Chairman then announced that the Subcommittee was investigating “subversion and subversive propaganda.” 54 This is a subject at least as broad and indefinite as the authorizing resolution of the Committee, if not more so.

Having exhausted the several possible indicia of the “question under inquiry,” we remain unenlightened as to the subject to which the questions asked petitioner were pertinent. Certainly, if the point is that obscure after trial and appeal, it was not adequately revealed to petitioner when he had to decide at his peril whether or not to answer. Fundamental fairness demands that no witness be compelled to make such a determination with so little guidance. Unless the subject matter has been made to appear with undisputable clarity, it is the duty of the investigative body, upon objection of the witness on grounds of pertinency, to state for the record the subject *215under inquiry at that time and the manner in which the propounded questions are pertinent thereto.55 To be meaningful, the explanation must describe what the topic under inquiry is and the connective reasoning whereby the precise questions asked relate to it.

The statement of the Committee Chairman in this case, in response to petitioner’s protest, was woefully inadequate to convey sufficient information as to the pertinency of the questions to the subject under inquiry. Petitioner was thus not accorded a fair opportunity to determine whether he was within his rights in refusing to answer, and his conviction is necessarily invalid under the Due Process Clause of the Fifth Amendment.

We are mindful of the complexities of modern government and the ample scope that must be left to the Congress as the sole constitutional depository of legislative power. Equally mindful are we of the indispensable function, in the exercise of that power, of congressional investigations. The conclusions we have reached in this case will not prevent the Congress, through its committees, from obtaining any information it needs for the proper fulfillment of its role in our scheme of government. The legislature is free to determine the kinds of data that should be collected. It is only those investigations that are conducted by use of compulsory process that give rise to a need to protect the rights of individuals against illegal encroachment. That protection can be readily achieved through procedures which prevent the separation of power from responsibility and which provide the constitutional requisites of fairness for witnesses. A measure of added care on the part of the House and the Senate in authorizing the use of compulsory process and by their committees in exercising that power would suffice. *216That is a small price to pay if it serves to uphold the principles of limited, constitutional government without constricting the power of the Congress to inform itself.

The judgment of the Court of Appeals is reversed, and the case is remanded to the District Court with instructions to dismiss the indictment.

It is so ordered.

Mr. Justice Burton and Mr. Justice Whittaker took no part in the consideration or decision of this case.

1

R. 153-163; Hearings before the House of Representatives Committee on Un-American Activities on Communist Activities in the Chicago Area—Part 1, 82d Cong., 2d Sess. 3737-3752.

2

R. 135-149; Hearings before the House of Representatives Committee on Un-American Activities on Investigation of Communist Activities in the Chicago Area—Part 2, 83d Cong., 2d Sess. 4243-4260.

3

R. 75; Hearings, supra, note 2, Part 3, at 4268.

4

Brief for Respondent, pp. 59-60.

5

R. 85-86; Hearings, supra, note 2, Part 3, at 4275.

6

There were nine citations of contempt voted at the same time. Petitioner's case was the second to be acted upon. There was no debate other than a statement by Representative Javits on a proposal to consolidate the legislative bodies investigating subversion. 100 Cong. Rec. 6382-6386. The resolution to prosecute petitioner passed by a voice vote.

There was lengthier discussion and a recorded vote on the first case considered by the House. Id., at 6375-6382. In none of the cases was there any debate on the merits of the witnesses’ conduct. Id., at 6375-6401.

7

The counts of the indictment were patterned from the sequence of the questioning by the Committee. Petitioner was asked separately about six persons, and these are the basis of the first six counts. The last count comprises the omnibus question that gave a list of twenty-five names for petitioner to identify. With two exceptions, the questions asked for knowledge of past membership in the Communist Party. The context of the interrogation indicates that the Committee’s concern was with such past conduct. Petitioner agreed to and did disclose his knowledge of those he believed to be present members.

8

“Now, we don’t claim on behalf of the Government that there is any right to expose for the purposes of exposure. And I don’t know that Congress has ever claimed any such right. But we do say, in the same breath, that there is a right to inform the public at the same time you inform the Congress.”

9

Coke, Fourth Institute, 15.

10

H. Comm. J. (1688-1693) 227; Jay v. Topham, 12 How. St. Tr. 822.

11

Proceedings against Richard Thompson, 8 How. St. Tr. 2; Wittke, The History of English Parliamentary Privilege, 50.

12

“Floyd, for uttering a few contemptible expressions, was degraded from his gentility, and to be held an infamous person; his testimony not to be received; to ride from the Fleet to Cheapside on horseback, without a saddle, with his face to the horse’s tail, and the tail in *190his hand, and then to stand two hours in the pillory, and to be branded in the forehead with the letter K; to ride four days after-wards in the same manner to Westminster, and then to stand two hours more in the pillory, with words on a paper in his hat showing his offence; to be whipped at the cart’s tail from the Fleet to Westminster Hall; to pay a fine of 5000Í.; and to be a prisoner in Newgate during his life." 1 De Lolme, The Rise and Progress of the English Constitution, 348.

13

H. L. J. (1620-1628) 110-111, 113, 116, 124, 125, 127, 132, 133-134, 183; Wittke, 76-77. See also Kelke, Constitutional Law and Cases, 155-156.

14

H. L. J. (1675-1681) 54-55.

15

Wittke, 122-123. With all his knavery, Wilkes was long a hero with certain persecuted groups in England. Here, streets and other public places have been named for him and his writings.

16

H. Comm. J. (1835) 533, 564-565, 571, 575.

17

Finer, Congressional Investigations: The British System, 18 U. of Chi. L. Rev. 521, 554-561; Smelser, Legislative Investigations: Safeguards for Witnesses: The Problem in Historical Perspective, 29 Notre Dame Law. 163, 167; Clokie & Robinson, Royal Commissions of Inquiry.

18

Finer, 559; Smelser, 167; Clokie & Robinson, 186-187.

19

See Landis, Constitutional Limitations on the Congressional Power of Investigation, 40 Harv. L. Rev. 153, 168-191; Potts, Power of Legislative Bodies to Punish for Contempt, 74 U. of Pa. L. Rev. 691, 719-725.

20

The first case to reach this Court was Anderson v. Dunn, 6 Wheat. 204, which upheld the power of the House of Representatives to reprimand a person for attempting to bribe a member of the House.

21

On December 31, 1827, the House Committee on Manufacturers was given the task of inquiring into the effect that the proposed upward revision in the tariff schedules would have upon domestic manufacture'rs. The power of the House to authorize a fact-finding inquiry in aid of legislation was seriously challenged. After full debate the investigation was authorized by a vote of 102 to 88. 4 Cong. Deb. 889.

22

The subject matter of the select committee was . . the late invasion and seizure of the armory and arsenal of the United States at Harper’s Ferry, in Virginia, by a band of armed men .... And that said committee [shall] report whether any and what legislation may, in their opinion, be necessary, on the part of the United States, for the future preservation of the peace of the country, or for the safety of the public property; and that said committee [shall] have power to send for persons and papers.” Cong. Globe, 36th Cong., 1st Sess. 141 (1859).

23

60 Stat. 828-829. All standing committees in the Senate were invested with the power of compulsory process. 60 Stat. 830-831. During the 83d Congress, two other standing committees in the House of Representatives, the Appropriations and Government Operations Committees, possessed that power. 99 Cong. Rec. 16-19.

24

The first court that was called upon to review the constitutional validity of a legislative inquiry was the New York Court of Common Pleas. The case arose out of the inquiry by the Common Council of New York into the conduct of the Police Department in 1855. Judge Charles Patrick Daly upheld the investigative power as implicit in the functions of a legislature, but ruled that the examination of witnesses must be confined to the subject under investigation. Applying this standard, he ruled that questions directed to the national origin of policemen were improper under the investigators’ authorizing resolution. Briggs v. Mackeller, 2 Abbott’s Practice Reports 30 (N. Y. Common Pleas 1855).

25

In re Chapman, 166 U. S. 661 (upheld conviction under R. S. § 102, forerunner of 2 U. S. C. § 192, for refusal to answer questions in inquiry into charges of corruption among certain Senators with respect to pending bill on sugar tariff); cf. Marshall v. Gordon, 243 U. S. 521.

26

Jurney v. MacCracken, 294 U. S. 125 (upheld power of Senate to punish as a contempt the action of a witness in allowing the destruction and removal of papers subject to the subpoena of a Senate committee; held that enactment of 2 U. S. C. § 192 did not impair contempt power of Houses of Congress).

27

The first reported case in which the claim of the privilege against self-incrimination was allowed in a congressional inquiry proceeding was United States v. Yukio Abe, 95 F. Supp. 991. Prior thereto, several state courts had held that legislative investigations were subject to the witness’ privilege not to accuse himself under state constitutions. Emery’s Case, 107 Mass. 172, decided in 1871 is the earliest. See also Ex parte Johnson, 187 S. C. 1, 196 S. E. 164.

28

E. g., Excerpts from Hearings before the House of Representatives Committee on Un-American Activities — Regarding Investigation of Communist Activities in Connection with the Atom Bomb, 80th Cong., 2d Sess. 5; N. Y. Herald Tribune, Sept. 6, 1948, p. 3, col. 6-7.

29

Appropriateness of the privilege has been upheld without question in many eases arising out of congressional inquiry. See, e. g., Starkovich v. United States, 231 F. 2d 411; Aiuppa v. United States, 201 F. 2d 287; United States v. Costello, 198 F. 2d 200; Marcello v. United States, 196 F. 2d 437; United States v. Di Carlo, 102 F. Supp. 597; United States v. Licavoli, 102 F. Supp. 607; United States v. Cohen, 101 F. Supp. 906; United States v. Jaffe, 98 F. Supp. 191; United States v. Fitzpatrick, 96 F. Supp. 491; United States v. Raley, 96 F. Supp. 495; United States v. Yukio Abe, 95 F. Supp. 991.

30

The first reported decision, made in 1947, grew out of the inquiry of the Un-American Activities Committee into certain organizations *197suspected of subversive actions. Subpoenas duces tecum had been issued calling for the correspondence and other records of these organizations. Refusals to comply were followed by prosecutions under 2 U. S. C. § 192. The District Court denied motions to dismiss the indictments in United States v. Bryan, 72 F. Supp. 58. The decision with respect to the First Amendment was affirmed in Barsky v. United States, 167 F. 2d 241.

31

See United States v. Rumely, 345 U. S. 41, 43-44; Lawson v. United States, 176 F. 2d 49, 51-52; Barsky v. United States, 167 F. 2d 241, 244-250; United States v. Josephson, 165 F. 2d 82, 90-92.

32

In a report to the House, the Committee declared:

“While Congress does not have the power to deny to citizens the right to believe in, teach, or advocate, communism, fascism, and naziism, it does have the right to focus the spotlight of publicity upon their activities . . . .” H. R. Rep. No. 2, 76th Cong., 1st Sess. 13.

A year later, the Committee reported that “. . . investigation to inform the American people ... is the real purpose of the House Committee.” H. R. Rep. No. 1476, 76th Cong., 3d Sess. 1-2.

A pamphlet issued by the Committee in 1951 stated that: “Exposure in a systematic way began with the formation of the House Committee on Un-American Activities, May 26, 1938.” The Committee believed itself commanded “. . . to expose people and organizations attempting to destroy this country. That is still its job and to that job it sticks.” 100 Things You Should Know About Communism, H. R. Doe. No. 136, 82d Cong., 1st Sess. 19, 67.

In its annual reports, the Committee has devoted a large part of its information to a public listing of names along with a summary of their activities. “. . . [T]he committee feels that the Congress and the American people will have a much clearer and fuller picture of the success and scope of communism in the United States by having set forth the names and, where possible, the positions occupied by individuals who have been identified as Communists, or former Communists, during the past year.” H. R. Rep. No. 2516, 82d Cong., 2d Sess. 6-7.

33

We are not concerned with the power of the Congress to inquire into and publicize corruption, maladministration or inefficiency in agencies of the Government. That was the only kind of activity described by Woodrow Wilson in Congressional Government when he wrote: “The informing function of Congress should be preferred even to its legislative function.” Id.., at 303. From the earliest times in its history, the Congress has assiduously performed an “informing function” of this nature. See Landis, Constitutional Limitations on the Congressional Power of Investigation, 40 Harv. L. Rev. 153, 168-194.

34

Compare the treatment of this point in Barenblatt v. United States, 240 F. 2d 875, 880-881; Morford v. United States, 176 F. 2d 54, 58; Eisler v. United States, 170 F. 2d 273, 278-279; United States v. Josephson, 165 F. 2d 82, 89; and United States v. Kamin, 136 F. Supp. 791, 800-801.

35

H. Res. 282, 75th Cong., 3d Sess., 83 Cong. Rec. 7568, 7586.

36

H. Res. 5, 79th Cong., 1st Sess., 91 Cong. Rec. 10, 15.

37

H. Res. 5, 83d Cong., 1st Sess., 99 Cong. Rec. 18, 24.

38

For contrasting views, see Morford v. United States, 176 F. 2d 54, 57-58, and Barsky v. United States, 167 F. 2d 241, 247-248.

39

The language of the resolution was obviously taken from the Dickstein resolution, which established the McCormack Committee in 1934 to study Nazi and other propaganda sent into the United States from foreign countries. H. Res. 198, 73d Cong., 2d Sess., 78 Cong. Rec. 4934, 4949.

40

In 1947, Judge Charles E. Clark, now Chief Judge of the Court of Appeals for the Second Circuit, wrote about the Committee: '‘Suffice it to say here that its range of activity has covered all varieties of organizations, including the American Civil Liberties Union, the C. I. 0., the National Catholic Welfare Conference, the Farmer-Labor party, the Federal Theatre Project, consumers’ organizations, various publications from the magazine ‘Time’ to the ‘Daily Worker,’ and varying forms and types of industry, of which the recent *203investigation of the movie industry is fresh in the public mind. While it has avoided specific definition of what it is seeking, it has repeatedly inquired as to membership in the Communist party and in other organizations which it regards as communist controlled or affected.” United States v. Josephson, 165 F. 2d 82, 95 (dissent). See also the dissenting opinion of Judge Henry W. Edgerton, now Chief Judge of the Court of Appeals for the District of Columbia Circuit, in Barsky v. United States, 83 U. S. App. D. C. 127, at 143, 167 F. 2d 241, at 257.

41

H. Res. 26, 76th Cong., 1st Sess., 84 Cong. Rec. 1098, 1127-1128; H. Res. 321, 76th Cong., 3d Sess., 86 Cong. Rec. 572, 604-605; H. Res. 90, 77th Cong., 1st Sess., 87 Cong. Rec. 886, 899; H. Res. 420, 77th Cong., 2d Sess., 88 Cong. Rec. 2282, 2297; H. Res. 65, 78th Cong., 1st Sess., 89 Cong. Rec. 795, 809-810.

42

91 Cong. Rec. 10, 15.

43

60 Stat. 812, 828.

44

H. Res. 5, 80th Cong., 1st Sess., 93 Cong. Rec. 38; H. Res. 5, 81st Cong., 1st Sess., 95 Cong. Rec. 10; H. Res. 7, 82d Cong., 1st Sess., 97 Cong. Rec. 17, 19; H. Res. 5, 83d Cong., 1st Sess., 99 Cong. Rec. 15; H. Res. 5, 84th Cong., 1st Sess., 101 Cong. Rec. 11.

45

This statute was passed in 1857 as a direct result of an incident which caused the Congress to feel that it needed more severe sanctions to compel disclosures than were available in the historical procedure of summoning the recalcitrant witness before the bar of either House of Congress and ordering him held in custody until he agreed to testify. Such imprisonment is valid only so long as the House remains in session. See Anderson v. Dunn, 6 Wheat. 204, 231; Eberling, Congressional Investigations, 180-184.

The immediate cause for adoption of the statute was an accusation by one J. W. Simonton, a newspaperman, that certain unnamed Congressmen were soliciting bribes on a matter pending before the legislature. Simonton was cited before the House of Representatives and refused to divulge the names of those implicated. In the course of that episode, the forerunner of 2 U. S. C. § 192 was passed in order “. . .to inflict a greater punishment than the committee believe the House possesses the power to inflict.” Cong. Globe, 34th *208Cong., 3d Sess. 405. See also id,., at 403-413, 426-433, 434-445. Thereafter, having been in custody more than two weeks, Simonton testified to the satisfaction of the committee and was discharged. 3 Hinds’ Precedents § 1669.

46

United States v. Harriss, 347 U. S. 612; United States v. Cardiff, 344 U. S. 174; Winters v. New York, 333 U. S. 507; Musser v. Utah, 333 U. S. 95; Lanzetta v. New Jersey, 306 U. S. 451.

47

United States v. Orman, 207 F. 2d 148; Bowers v. United States, 202 F. 2d 447; United States v. Kamin, 135 F. Supp. 382, 136 F. Supp. 791.

48

United States v. Josephson, 165 F. 2d 82, 88.

49

“The committee will be in order. I should like to make an opening statement regarding our work here in the city of Chicago. The Congress of the United States, realizing that there are individuals and elements in this country whose aim it is to subvert our constitutional form of government, has established the House Committee on Un-American Activities. In establishing this committee, the Congress has directed that we must investigate and hold hearings, either by the full committee or by a subcommittee, to ascertain the extent and success of subversive activities directed against these United States.

“On the basis of these investigations and hearings, the Committee on Un-American Activities reports its findings to the Congress and makes recommendations from these investigations and hearings for new legislation. As a result of this committee’s investigations and hearings, the Internal Security Act of 1950 was enacted.

"Over the past fifteen years this committee has been in existence, both as a special and permanent committee, it has made forty-seven recommendations to the Congress to insure proper security against subversion. I am proud to be able to state that of these forty-seven recommendations, all but eight have been acted upon in one way or another. Among these recommendations which the Congress has not acted upon are those which provide that witnesses appearing before congressional committees be granted immunity from prosecution on the information they furnish.

“The committee has also recommended that evidence secured from confidential devices be admissible in cases involving the national security. The executive branch of Government has now also asked the Congress for such legislation. A study is now being made of various bills dealing with this matter.

“The Congress has also referred to the House Committee on Un-American Activities a bill which would amend the National Security Act of 1950. This bill, if enacted into law, would provide that the Subversive Activities Control Board should, after suitable hearings and procedures, be empowered to find if certain labor organizations are in fact Communist-controlled action groups. Following this action, such labor groups would not have available the use of the *211National Labor Relations Board as they now have under the provisions of the Labor-Management Relations Act of 1947.

“During the first session of this 83rd Congress, the House Un-American Activities Committee has held hearings in Los Angeles and San Francisco, California; Albany and New York City, New York; Philadelphia, Pennsylvania, and Columbus, Ohio. We are here in Chicago, Illinois, realizing that this is the center of the great mid-western area of the United States.

“It cannot be said that subversive infiltration has had a greater nor a lesser success in infiltrating this important area. The hearings today are the culmination of an investigation that has been conducted by the committee's competent staff and is a part of the committee’s intention for holding hearings in various parts of the country.

“The committee has found that by conducting its investigations and holding hearings in various parts of the country, it has been able to secure a fuller and more comprehensive picture of subversive efforts throughout our nation. Every witness who has been subpoenaed to appear before the committee here in Chicago, as in all hearings conducted by this committee, are [sic] known to possess information which will assist the committee in performing its directed function to the Congress of the United States.” (R. 43-44; Hearing, supra, note 2, Part 1, at 4165-4166.)

50

The Committee convened in executive session on January 22, 1953, and adopted the following resolution:

“Be It Resolved, that the Chairman shall have authority from time to time to appoint subcommittees composed of one or more members of the Committee on Un-American Activities for the purpose of performing any and all acts which the Committee as a whole is authorized to do.” (R. 91.)

51

The original resolution authorizing subcommittees was amended on March 3, 1954, to require any subcommittee to consist of at least three members, two of whom-could constitute a quorum. (R. 92.)

Petitioner appeared before a subcommittee composed at the outset of four members. After a recess in the course of his testimony, only two committeemen were present. It was during this latter phase of his testimony that petitioner refused to answer the questions involved in this case.

52

The bill pending at the time of the Chairman’s remarks, March 15, 1954, and when petitioner testified a month later was H. R. 7487, 100 Cong. Ree. 763. No action was ever taken on this proposal. Introduced by Representative Velde, it would have withdrawn the rights, privileges and benefits under the National Labor Relations Act of any labor organization which was substantially directed, dominated or controlled by persons who were or ever had been members of a “Communist-action organization,” as that phrase is used in the Internal Security Act.

On July 6, 1954, after extensive hearings, the Senate Judiciary Committee reported favorably on S. 3706, a bill drafted by that committee to amend the Internal Security Act. Two days later, Representative Velde introduced H. R. 9838, which was identical to S. 3706. These bills eventually became law. 68 Stat. 775. The Act created the concept of a “Communist infiltrated organization,” and part of its provisions declared that a labor union that came within that definition should be barred from the rights, privileges and benefits of the National Labor Relations Act. The same sanctions were applied to a labor group that was a “Communist-action” or “Communist-front organization” under the original Internal Security Act.

53

The first four witnesses testified principally about the Communist Party activities of an employee of the National Cancer Institute of the United States Public Health Service. A Chicago attorney related to the Subcommittee his experiences with Communist youth organizations during his college days. The sixth witness told of her work as a district organizer for the Communist Party in Montana, Wyoming, Idaho and the Dakotas during the 1930’s.

54

“This committee is set up by the House of Representatives to investigate subversion and subversive propaganda and to report to the House of Representatives for the purpose of remedial legislation.

“The House of Representatives has by a very clear majority, a very large majority, directed us to engage in that type of work, and so we do, as a committee of the House of Representatives, have the authority, the jurisdiction, to ask you concerning your activities in the Communist Party, concerning your knowledge of any other persons who are members of the Communist Party or who have been members of the Communist Party, and so, Mr. Watkins, you are directed to answer the question propounded to you by counsel.” (R. 86; Hearings, supra, note 2, Part 3, at 4275-4276.)

55

Cf. United States v. Kamin, 136 F. Supp. 791, 800.

Mr. Justice Frankfurter,

concurring.

I deem it important to state what I understand to be the Court’s holding. Agreeing with its holding, I join its opinion.

The power of the Congress to punish for contempt of its authority is, as the Court points out, rooted in history. It has been acknowledged by this Court since 1821. Anderson v. Dunn, 6 Wheat. 204. Until 1857, Congress was content to punish for contempt through its own process. By the Act of January 24, 1857, 11 Stat. 155, as amended by the Act of January 24, 1862, 12 Stat. 333, Congress provided that, “in addition to the pains and penalties now existing” (referring of course to the power of Congress itself to punish for contempt), “contumacy in a witness called to testify in a matter properly under consideration by either House, and deliberately refusing to answer questions pertinent thereto, shall be a misdemeanor against the United States.” In re Chapman, 166 U. S. 661, 672. This legislation is now 2 U. S. C. § 192. By thus making the federal judiciary the affirmative agency for enforcing the authority that underlies the congressional power to punish for contempt, Congress necessarily brings into play the specific provisions of the Constitution relating to the prosecution of offenses and those implied restrictions under which courts function.

*217To turn to the immediate problem before us, the scope of inquiry that a committee is authorized to pursue must be defined with sufficiently unambiguous clarity to safeguard a witness from the hazards of vagueness in the enforcement of the criminal process against which the Due Process Clause protects. The questions must be put with relevance and definiteness sufficient to enable the witness to know whether his refusal to answer may lead to conviction for criminal contempt and to enable both the trial and the appellate courts readily to determine whether the particular circumstances justify a finding of guilt.

While implied authority for the questioning by the Committee, sweeping as was its inquiry, may be squeezed out of the repeated acquiescence by Congress in the Committee’s inquiries, the basis for determining petitioner’s guilt is not thereby laid. Prosecution for contempt of Congress presupposes an adequate opportunity for the defendant to have awareness of the pertinency of the information that he has denied to Congress. And the basis of such awareness must be contemporaneous with the witness’ refusal to answer and not at the trial for it. Accordingly, the actual scope of the inquiry that the Committee was authorized to conduct and the relevance of the questions to that inquiry must be shown to have been luminous at the time when asked and not left, at best, in cloudiness. The circumstances of this case were wanting in these essentials.

Mr. Justice Clark,

dissenting.

As I see it the chief fault in the majority opinion is its mischievous curbing of the informing function of the Congress. While I am not versed in its procedures, my experience in the Executive Branch of the Government leads me to believe that the requirements laid down in the opinion for the operation of the committee system of *218inquiry are both unnecessary and unworkable. It is my purpose to first discuss this phase of the opinion and then record my views on the merits of Watkins’ case.

I.

It may be that at times the House Committee on Un-American Activities has, as the Court says, “conceived of its task in the grand view of its name.” And, perhaps, as the Court indicates, the rules of conduct placed upon the Committee by the House admit of individual abuse and unfairness. But that is none of our affair. So long as the object of a legislative inquiry is legitimate and the questions propounded are pertinent thereto, it is not for the courts to interfere with the committee system of inquiry. To hold otherwise would be an infringement on the power given the Congress to inform itself, and thus a trespass upon the fundamental American principle of separation of powers. The majority has substituted the judiciary as the grand inquisitor and supervisor of congressional investigations. It has never been so.

II.

Legislative committees to inquire into facts or conditions for assurance of the public welfare or to determine the need for legislative action have grown in importance with the complexity of government. The investigation that gave rise to this prosecution is of the latter type. Since many matters requiring statutory action lie in the domain of the specialist or are unknown without testimony from informed witnesses, the need for information has brought about legislative inquiries that have used the compulsion of the subpoena to lay bare needed facts and a statute, 2 U. S. C. § 192 here involved, to punish recalcitrant witnesses. The propriety of investigations has long been recognized and rarely curbed by the courts, though *219constitutional limitations on the investigatory powers are admitted.1 The use of legislative committees to secure information follows the example of the people from whom our legislative system is derived. The British method has variations from that of the United States but fundamentally serves the same purpose — the enlightenment of Parliament for the better performance of its duties. There are standing committees to carry on the routine work, royal commissions to grapple with important social or economic problems, and special tribunals of inquiry for some alleged offense in government.2 Our Congress has since its beginning used the committee system to inform itself. It has been estimated that over 600 investigations have been conducted since the First Congress. They are “a necessary and appropriate attribute of the power to legislate . . . .” McGrain v. Daugherty, 273 U. S. 135, 175 (1927).

The Court indicates that in this case the source of the trouble lies in the “tremendous latitude” given the Un-American Activities Committee in the Legislative Reorganization Act.3 It finds that the Committee “is *220allowed, in essence, to define its own authority, [and] to choose the direction and focus of its activities.” This, of course, is largely true of all committees within their respective spheres. And, while it is necessary that the “charter,” as the opinion calls the enabling resolution, “spell out [its] jurisdiction and purpose,” that must necessarily be in more or less general terms. An examination of the enabling resolutions of other committees reveals the extent to which this is true.

Permanent or standing committees of both Houses have been given power in exceedingly broad terms. For example, the Committees on the Armed Services have jurisdiction over “Common defense generally”;4 the Committees on Interstate and Foreign Commerce have *221jurisdiction over “Interstate and foreign commerce generally”; 5 and the Committees on Appropriation have jurisdiction over “Appropriation of the revenue for the support of the Government.”6 Perhaps even more important for purposes of comparison are the broad authorizations given to select or special committees established by the Congress from time to time. Such committees have been “authorized and directed” to make full and complete studies “of whether organized crime utilizes the facilities of interstate commerce or otherwise operates in interstate commerce”; 7 “of ... all lobbying activities intended to influence, encourage, promote, or retard legislation” ;8 “to determine the extent to which current *222literature . . . containing immoral, [or] obscene . . . matter, or placing improper emphasis on crime . . . are being made available to the people of the United States . . .”;9 and “of the extent to which criminal or other improper practices . . . are, or have been, engaged in in the field of labor-management relations ... to the detriment of the interests of the public . . . 10 (Emphasis added in each example.) Surely these authorizations permit the committees even more “tremendous latitude” than the “charter” of the Un-American Activities Committee. Yet no one has suggested that the powers granted were too broad. To restrain and limit the breadth of investigative power of this Committee necessitates the similar handling of all other committees. The resulting restraint imposed on the committee system appears to cripple the system beyond workability.

The Court finds fault with the use made of compulsory process, power for the use of which is granted the Com*223mittee in the Reorganization Act. While the Court finds that the Congress is free “to determine the kinds of data” it wishes its committees to collect, this has led, the Court says, to an encroachment on individual rights through the abuse of process. To my mind this indicates a lack of understanding of the problems facing such committees. I am sure that the committees would welcome voluntary disclosure. It would simplify and relieve their burden considerably if the parties involved in investigations would come forward with a frank willingness to cooperate. But everyday experience shows this just does not happen. One needs only to read the newspapers to know that the Congress could gather little “data” unless its committees had, unfettered, the power of subpoena. In fact, Watkins himself could not be found for appearance at the first hearing and it was only by subpoena that he attended the second. The Court generalizes on this crucial problem saying “added care on the part of the House and the Senate in authorizing the use of compulsory process and by their committees in exercising that power would suffice.” It does not say how this “added care” could be applied in practice; however, there are many implications since the opinion warns that “procedures which prevent the separation of power from responsibility” would be necessary along with “constitutional requisites of fairness for witnesses.” The “power” and “responsibility” for the investigations are, of course, in the House where the proceeding is initiated. But the investigating job itself can only be done through the use of committees. They must have the “power” to force compliance with their requirements. If the rule requires that this power be retained in the full House then investigations will be so cumbrous that their conduct will be a practical impossibility. As to “fairness for witnesses” there is nothing in the record showing any abuse of Watkins. If anything, the Committee was abused by his recalcitrance.

*224While ambiguity prevents exactness (and there is “vice in vagueness” the majority reminds), the sweep of the opinion seems to be that “preliminary control” of the Committee must be exercised. The Court says a witness’ protected freedoms cannot “be placed in danger in the absence of a clear determination by the House or the Senate that a particular inquiry is justified by a specific legislative need.” Frankly I do not see how any such procedure as “preliminary control” can be effected in either House of the Congress. What will be controlled preliminarily? The plans of the investigation, the necessity of calling certain witnesses, the questions to be asked, the details of subpoenas duces tecum, etc.? As it is now, Congress is hard pressed to find sufficient time to fully debate and adopt all needed legislation. The Court asserts that “the Congress has practically abandoned its original practice of utilizing the coercive sanction of contempt proceedings at the bar of the House.” This was to be expected. It may be that back in the twenties and thirties Congress could spare the time to conduct contempt hearings, but that appears impossible now. The Court places a greater burden in the conduct of contempt cases before the courts than it does before “the bar of the House.” It cites with approval cases of contempt tried before a House of the Congress where no more safeguards were present than we find here. In contempt prosecutions before a court, however, the majority places an investigative hearing on a par with a criminal trial, requiring that “knowledge of the subject to which the interrogation is deemed pertinent . . . must be available [to the witness] with the same degree of explicitness and clarity that the Due Process Clause requires in the expression of any element of a criminal offense.” I know of no such claim ever being made before. Such a requirement has never been thought applicable to investigations and is wholly out of place when related to the informing func*225tion of the Congress. See Frankfurter, Hands Off The Investigations, 38 New Republic, May 21, 1924, p. 329, 65 Cong. Rec. 9080-9082. The Congress does not have the facts at the time of the investigation for it is the facts that are being sought. In a criminal trial the investigation has been completed and all of the facts are at hand. The informing function of the Congress is in effect “a study by the government of circumstances which seem to call for study in the public interest.” See Black, Inside a Senate Investigation, 172 Harper’s Magazine, Feb. 1936, pp. 275, 278. In the conduct of such a proceeding it is impossible to be as explicit and exact as in a criminal prosecution. If the Court is saying that its new rule does not apply to contempt cases tried before the bar of the House affected, it may well lead to trial of all contempt cases before the bar of the whole House in order to avoid the restrictions of the rule. But this will not promote the result desired by the majority. Summary treatment, at best, could be provided before the whole House because of the time factor, and such treatment would necessarily deprive the witness of many of the safeguards in the present procedures. On review here the majority might then find fault with that procedure.

III.

Coming to the merits of Watkins’ case, the Court reverses the judgment because: (1) The subject matter of the inquiry was not “made to appear with undisputable clarity” either through its “charter” or by the Chairman at the time of the hearing and, therefore, Watkins was deprived of a clear understanding of “the manner in which the propounded questions [were] pertinent thereto”; and (2) the present committee system of inquiry of the House, as practiced by the Un-American Activities Committee, does not provide adequate safeguards for the protection *226of the constitutional right of free speech. I subscribe to neither conclusion.

Watkins had been an active leader in the labor movement for many years and had been identified by two previous witnesses at the Committee’s hearing in Chicago as a member of the Communist Party. There can be no question that he was fully informed of the subject matter of the inquiry. His testimony reveals a complete knowledge and understanding of the hearings at Chicago. There the Chairman had announced that the Committee had been directed “to ascertain the extent and success of subversive activities directed against these United States [and] On the basis of these investigations and hearings . . . [report] its findings to the Congress and [make] recommendations ... for new legislation.” He pointed to the various laws that had been enacted as a result of Committee recommendations. He stated that “The Congress has also referred to the House Committee on Un-American Activities a bill which would amend the National Security Act of 1950” which, if made law, would restrict the availability of the Labor Act to unions not “in fact Communist-controlled action groups.” The Chairman went on to say that “It cannot be said that subversive infiltration has had a greater nor a lesser success in infiltrating this important area. The hearings today are the culmination of an investigation . . . . Every witness who has been subpoenaed to appear before the committee here in Chicago . . . [is] known to possess information which will assist the Committee in performing its directed function to the Congress of the United States.”

A subpoena had issued for Watkins to appear at the Chicago hearings but he was not served. After Watkins was served the hearing in question was held in Washington, D. C. Reference at this hearing was made to the one conducted in Chicago. Watkins came before the *227Committee with, a carefully prepared statement. He denied certain testimony of the previous witnesses and declared that he had never been a “card-carrying member” of the Party. He admitted that for the period 1942-1947 he “cooperated with the Communist Party . . . participated in Communist activities . . . made contributions ... attended caucuses at [his union's] convention at which Communist Party officials were present . . . [and] freely cooperated with the Communist Party . . . This indicated that for a five-year period he, a union official, was cooperating closely with the Communist Party even permitting its officials to attend union caucuses. For the last two years of this liaison the Party had publicly thrown off its cloak of a political party. It was a reconstituted, militant group known to be dedicated to the overthrow of our Government by force and violence. In this setting the Committee attempted to have Watkins identify 30 persons, most of whom were connected with labor unions in some way. While one “operated a beauty parlor” and another was “a watchmaker,” they may well have been “drops” or other functionaries in the program of cooperation between the union and the Party. It is a non sequitur for the Court to say that since “almost a quarter of the persons on the list are not labor people, the inference becomes strong that the subject before the Subcommittee was not defined in terms of Communism in labor.” I submit that the opposite is true.

IV.

I think the Committee here was acting entirely within its scope and that the purpose of its inquiry was set out with “undisputable clarity.” In the first place, the authorizing language of the Reorganization Act11 must be read as a whole, not dissected. It authorized investi*228gation into subversive activity, its extent, character, objects, and diffusion. While the language might have been more explicit than using such words as “un-Amer-ican,” or phrases like “principle of the form of government,” still these are fairly well understood terms. We must construe them to give them meaning if we can. Our cases indicate that rather than finding fault with the use of words or phrases, we are bound to presume that the action of the legislative body in granting authority to the Committee was with a legitimate object “if [the action] is capable of being so construed.” (Emphasis added.) People ex rel. McDonald v. Keeler, 99 N. Y. 463, 487, 2 N. E. 615, 627-628 (1885), as quoted and approved in McGrain v. Daugherty, supra, at 178. Before we can deny the authority “it must be obvious that” the Committee has “exceeded the bounds of legislative power.” Tenney v. Brandhove, 341 U. S. 367, 378 (1951). The fact that the Committee has often been attacked has caused close scrutiny of its acts by the House as a whole and the House has repeatedly given the Committee its approval. “Power” 'and “responsibility” have not been separated. But the record in this case does not stop here. It shows that at the hearings involving Watkins, the Chairman made statements explaining the functions of the Committee.12 And, furthermore, Watkins’ action at the hear*229ing clearly reveals that he was well acquainted with the purpose of the hearing. It was to investigate Communist infiltration into his union. This certainly falls within the grant of authority from the Reorganization Act and the House has had ample opportunity to limit the investigative scope of the Committee if it feels that the Committee has exceeded its legitimate bounds.

The Court makes much of petitioner’s claim of “exposure for exposure’s sake” and strikes at the purposes of the Committee through this catch phrase. But we are bound to accept as the purpose of the Committee that stated in the Reorganization Act together with the statements of the Chairman at the hearings involved here. Nothing was said of exposure. The statements of a single Congressman cannot transform the real purpose of the Committee into something not authorized by the parent resolution. See United States v. Rumely, 345 U. S. 41 (1953); Sinclair v. United States, 279 U. S. 263, 290, 295 (1929). The Court indicates that the questions propounded were asked for exposure’s sake and had no pertinency to the inquiry. It appears to me that they were entirely pertinent to the announced purpose of the Committee’s inquiry. Undoubtedly Congress has the power to inquire into the subjects of communism and the Communist Party. American Communications Assn. v. Douds, 339 U. S. 382 (1950). As a corollary of the congressional power to inquire into such subject matter, the Congress, through its committees, can legitimately seek to identify individual members of the Party. Barsky v. United States, 83 U. S. App. D. C. 127, 167 F. 2d 241 (1948), cert. denied, 334 U. S. 843. See also Lawson v. United States, 85 U. S. App. D. C. 167, 170-171, 176 F. 2d 49, 52-53 *230(1949), cert. denied, 339 U. S. 934; United States v. Josephson, 165 F. 2d 82, 90-92 (1947), cert. denied, 333 U. S. 838.

The pertinency of the questions is highlighted by the need for the Congress to know the extent of infiltration of communism in labor unions. This technique of infiltration was that used in bringing the downfall of countries formerly free but now still remaining behind the Iron Curtain. The Douds case illustrates that the Party is not an ordinary political party and has not been at least since 1945. Association with its officials is not an ordinary association. Nor does it matter that the questions related to the past. Influences of past associations often linger on as was clearly shown in the instance of the witness Matusow and others. The techniques used in the infiltration which admittedly existed here might well be used again in the future. If the parties about whom Watkins was interrogated were Communists and collaborated with him, as a prior witness indicated, an entirely new area of investigation might have been opened up. Watkins’ silence prevented the Committee from learning this information which could have been vital to its future investigation. The Committee was likewise entitled to elicit testimony showing the truth or falsity of the prior testimony of the witnesses who had involved Watkins and the union with collaboration with the Party. If the testimony was untrue a false picture of the relationship between the union and the Party leaders would have resulted. For these reasons there were ample indications of the pertinency of the questions.

y.

The Court condemns the long-established and long-recognized committee system of inquiry of the House because it raises serious questions concerning the protection it affords to constitutional rights. It concludes that com*231pelling a witness to reveal his “beliefs, expressions or associations” impinges upon First Amendment rights. The system of inquiry, it says, must “insure that the Congress does not unjustifiably encroach upon an individual’s right to privacy nor abridge his liberty of speech, press, religion or assembly.” In effect the Court honors Watkins’ claim of a “right to silence” which brings all inquiries, as we know, to a “dead end.” I do not see how any First Amendment rights were endangered here. There is nothing in the First Amendment that provides the guarantees Watkins claims. That Amendment was designed to prevent attempts by law to curtail freedom of speech. Whitney v. California, 274 U. S. 357, 375 (1927). It forbids Congress from making any law “abridging the freedom of speech, or of the press.” It guarantees Watkins’ right to join any organization and make any speech that does not have an intent to incite to crime. Dennis v. United States, 341 U. S. 494 (1951). But Watkins was asked whether he knew named individuals and whether they were Communists. He refused to answer on the ground that his rights were being abridged. What he was actually seeking to do was to protect his former associates, not himself, from embarrassment. He had already admitted his own involvement. He sought to vindicate the rights, if any, of his associates. It is settled that one cannot invoke the constitutional rights of another. Tileston v. Ullman, 318 U. S. 44, 46 (1943).

As already indicated, even if Watkins’ associates were on the stand they could not decline to disclose their Communist connections on First Amendment grounds. While there may be no restraint by the Government of one’s beliefs, the right of free belief has never been extended to include the withholding of knowledge of past events or transactions. There is no general privilege of silence. The First Amendment does not make speech or silence permissible to a person in such measure as he *232chooses. Watkins has here exercised his own choice as to when he talks, what questions he answers, and when he remains silent. A witness is not given such a choice by the Amendment. Remote and indirect disadvantages such as “public stigma, scorn and obloquy” may be related to the First Amendment, but they are not enough to block investigation. The Congress has recognized this since 1862 when it first adopted the contempt section, R. S. § 103, as amended, 2 U. S. C. § 193, declaring that no witness before a congressional committee may refuse to testify “upon the ground that his testimony to such fact or his production of such paper may tend to disgrace him or otherwise render him infamous.” See also McGrain v. Daugherty, supra, at 179-180; United States v. Josephson, 165 F. 2d 82, 89 (1947), cert. denied, 333 U. S. 838. See also Report on Congressional Investigations, Assn. of the Bar of the City of New York, 3-4 (1948).

We do not have in this case unauthorized, arbitrary, or unreasonable inquiries and disclosures with respect to a witness’ personal and private affairs so ably and properly denounced in the Sinclair case, supra, at 291-292. This inquiry is far different from the cases relied upon by the Court. There is no analogy to the case of Richard Thompson 13 involving the sermons of clergymen. It is not Floyd’s14 case involving criticism of the royal family. There is no resemblance to John Wilkes’ struggle for a seat in Parliament. It is not Briggs15 where the prosecutor sought to develop the national origin of policemen. It is not Kilbourn16 involving a private real estate pool. *233Nor is it Quinn,17 Emspak,18 or Bart19 involving the Fifth Amendment. It is not Rumely20 involving the interpretation of a lobbying statute. Nor is this “a new kind of congressional inquiry unknown in prior periods of American history ... [i e,] a broad scale intrusion into the lives and affairs of private citizens.” As I see it only the setting is different. It involves new faces and new issues brought about by new situations which the Congress feels it is necessary to control in the public interest. The difficulties of getting information are identical if not greater. Like authority to that always used by the Congress is employed here and in the same manner so far as congressional procedures are concerned. We should afford to Congress the presumption that it takes every precaution possible to avoid unnecessary damage to reputations. Some committees have codes of procedure, and others use the executive hearing technique to this end. The record in this case shows no conduct on the part of the Un-American Activities Committee that justifies condemnation. That there may have been such occasions is not for us to consider here. Nor should we permit its past transgressions, if any, to lead to the rigid restraint of all congressional committees. To carry on its heavy responsibility the compulsion of truth that does not incriminate is not only necessary to the Congress but is permitted within the limits of the Constitution.

1

United States v. Rumely, 345 U. S. 41 (1953); Sinclair v. United States, 279 U. S. 263 (1929); Reed v. County Commissioners, 277 U. S. 376 (1928); McGrain v. Daugherty, 273 U. S. 135 (1927); Landis, Constitutional Limitations on the Congressional Power of Investigation, 40 Harv. L. Rev. 153 (1926).

2

Symposium on Congressional Investigations, 18 U. of Chi. L. Rev. 421, Finer, The British System, 521, 532, 554, 561 (1951).

3

The Committee originated in 1938 under H. Res. 282, 75th Cong., 3d Sess., 83 Cong. Rec. 7568, and was patterned after a resolution of 1934 authorizing the investigation of Nazi propaganda. H. Res. 198, 73d Cong., 2d Sess., 78 Cong. Rec. 4934. The resolution read much the same as the present authority of the Committee which is quoted below. By a succession of House Resolutions (H. Res. 26, 76th Cong., 1st Sess., 84 Cong. Rec. 1098; H. Res. 321, 76th Cong., 3d Sess., 86 Cong. Rec. 572; H. Res. 90, 77th Cong., 1st Sess., 87 Cong. Rec. 886; H. Res. 420, 77th Cong., 2d Sess., 88 Cong. Rec. 2282; H. Res. 65, 78th Cong., 1st Sess., 89 Cong. Rec. 795) the *220Committee continued in existence until in 1945, by amendment of the House Rules, it was made a standing committee. 91 Cong. Rec. 10, 15. The Legislative Reorganization Act of 1946 retained it as one of the standing committees and provided:

“All proposed legislation, messages, petitions, memorials, and other matters relating to the subjects listed under the standing committees named below shall be referred to such committees, respectively: . . .”

“(q) . . . (2) The Committee on Un-American Activities, as a whole or by subcommittee, is authorized to make from time to time investigations of (i) the extent, character, and objects of un-American propaganda activities in the United States, (ii) the diffusion within the United States of subversive and un-American propaganda that is instigated from foreign countries or of a domestic origin and attacks the principle of the form of government as guaranteed by our Constitution, and (iii) all other questions in relation thereto that would aid Congress in any necessary remedial legislation.” 60 Stat. 823, 828.

The Committee is authorized to sit and act at any time, anywhere in the United States and to require the attendance of witnesses and the production of books and papers. A resolution of the Eighty-third Congress adopted the Rules of the previous Congresses as amended by the Legislative Reorganization Act of 1946. H. Res. 5, 83d Cong., 1st Sess., 99 Cong. Rec. 15, 16, 18, 24.

4

60 Stat. 815, 824.

5

60 Stat. 817, 826.

6

60 Stat. 815, 824.

7

S. Res. 202, 81st Cong., 2d Sess., in pertinent part provides:

“authorized and directed to make a full and complete study and investigation of whether organized crime utilizes the facilities of interstate commerce or otherwise operates in interstate commerce in furtherance of any transactions which are in violation of the law of the United States or of the State in which the transactions occur, and, if so, the manner and extent to which, and the identity of the persons, firms, or corporations by which such utilization is being made, what facilities are being used, and whether or not organized crime utilizes such interstate facilities or otherwise operates in interstate commerce for the development of corrupting influences in violation of law of the United States or of the laws of any State: Provided, however, That nothing contained herein shall authorize (1) the recommendation of any change in the laws of the several States relative to gambling, or (2) any possible interference with the rights of the several States to prohibit, legalize, or in any way regulate gambling within their borders.'’

8

H. Res. 298, 81st Cong., 1st Sess., in pertinent part provides:

“authorized and directed to conduct a study and investigation of (1) all lobbying activities intended to influence, encourage, promote, or retard legislation; and (2) all activities of agencies of the Federal Government intended to influence, encourage, promote, or retard legislation.”

9

H. Res. 596, 82d Cong., 2d Sess., in pertinent part provides:

“authorized and directed to conduct a full and complete investigation and study (1) to determine the extent to which current literature — books, magazines, and comic books — containing immoral, obscene, or otherwise offense matter, or placing improper emphasis on crime, violence, and corruption, are being made available to the people of the United States through the United States mails and otherwise; and (2) to determine the adequacy of existing law to prevent the publication and distribution of books containing immoral, offensive, and other undesirable matter.”

10

S. Res. 74, 85th Cong., 1st Sess., in pertinent part provides:

“authorized and directed to conduct an investigation and study of the extent to which criminal or other improper practices or activities are, or have been, engaged in in the field of labor-management relations or in groups or organizations of employees or employers to the detriment of the interests of the public, employers or employees, and to determine whether any changes are required in the laws of the United States in order to protect such interests against the occurrence of such practices or activities.”

11

See note 3, supra.

12

See supra, at p. 226. See also the statement by Congressman Velde, Chairman of the Committee on Un-American Activities, April 29, 1954, at Washington, D. C., where Mr. Velde stated, inter alia: “This committee is set up by the House of Representatives to investigate subversion and subversive propaganda and to report to the House of Representatives for the purpose of remedial legislation.

“The House of Representatives has by a very clear majority, a very large majority, directed us to engage in that type of work, and so we do, as a committee of the House of Representatives, have the authority, the jurisdiction, to ask you concerning your activities in the Communist Party, concerning your knowledge of any other persons *229who are members of the Communist Party or who have been members of the Communist Party, and so, Mr. Watkins, you are directed to answer the question propounded to you by counsel.”

13

Proceedings against Richard Thompson, 8 How. St. Tr. 2 (1680).

14

See 1 De Lolme, The Rise and Progress of the English Constitution (1838), at 347-348.

15

Briggs v. Mackellar, 2 Abb. Pr. 30, 65 (N. Y. Common Pleas 1855).

16

Kilbourn v. Thompson, 103 U. S. 168 (1881).

17

Quinn v. United States, 349 U. S. 155 (1955).

18

Emspak v. United States, 349 U. S. 190 (1955).

19

Bart v. United States, 349 U. S. 219 (1955).

20

United States v. Rumely, 345 U. S. 41 (1953).

EASTLAND et al. v. UNITED STATES SERVICEMEN’S FUND ET AL.

No. 73-1923.

Argued January 22, 1975

Decided May 27, 1975

*492Burger, C. J., delivered the opinion of the Court, in which White, Blackmun, Powell, and Rehnquist, JJ., joined. Marshall, J., filed an opinion concurring in the judgment, in which Brennan and Stewart, JJ., joined, -post, p. 513. Douglas, J., filed a dissenting opinion, post, p. 518.

Herbert J. Miller, Jr., argued the cause for petitioners. With him on the brief were Nathan Lewin and A. Raymond Randolph, Jr.

Nancy Stearns and Jeremiah S. Gutman argued the cause and filed a brief for respondents.

Mr. Chief Justice Burger

delivered the opinion of the Court.

We granted certiorari to decide whether a federal court may enjoin the issuance by Congress of a subpoena duces tecum that directs a bank to produce the bank records of an organization which claims a First Amend*493ment privilege status for those records on the ground that they are the equivalent of confidential membership lists. The Court of Appeals for the District of Columbia Circuit held that compliance with the subpoena “would invade the constitutional rights” of the organization, and that judicial relief is available to prevent implementation of the subpoena.

I

In early 1970 the Senate Subcommittee on Internal Security was given broad authority by the Senate to “make a complete and continuing study and investigation of . . . the administration, operation, and enforcement of the Internal Security Act of 1950 . . . .” S. Res. 341, 91st Cong., 2d Sess. (1970). The authority encompassed discovering the “extent, nature, and effect of subversive activities in the United States,” and the resolution specifically directed inquiry concerning “infiltration by persons who are or may be under the domination of the foreign government . . . .” Ibid. See also S. Res. 366, 81st Cong., 2d Sess. (1950). Pursuant to that mandate the Subcommittee began an inquiry into the activities of respondent United States Servicemen’s Fund, Inc. (USSF).

USSF describes itself as a nonprofit membership corporation supported by contributions.1 Its stated purpose is “to further the welfare of persons who have served or are presently serving in the military.” To accomplish its declared purpose USSF has engaged in various activities2 directed at United States servicemen. • *494It established “coffeehouses” near domestic military installations, and aided the publication of “underground” newspapers for distribution on American military installations throughout the world. The coffeehouses were meeting places for servicemen, and the newspapers were specialized publications which USSF claims dealt with issues of concern to servicemen. Through these operations USSF attempted to communicate to servicemen its philosophy and attitudes concerning United States involvement in Southeast Asia. USSF claims the coffeehouses and newspapers became “the focus of dissent and expressions of opposition within the military toward the war in [Southeast Asia].”3

In the course of its investigation of USSF, the Subcommittee concluded that a prima facie showing had been made of the need for further investigation, and it resolved that appropriate subpoenas, including subpoenas duces tecum could be issued. Petitioner Eastland, a United States Senator, is, as he was then, Chairman of the Subcommittee. On May 28, 1970, pursuant to the above authority, he signed a subpoena duces tecum, issued on behalf of the Subcommittee, to the bank where USSF then had an account. The subpoena commanded the bank to produce by June 4, 1970:

“any and all records appertaining to or involving the account or accounts of [USSF]. Such records to comprehend papers, correspondence, statements, checks, deposit slips and supporting documentation, or microfilm thereof within [the bank’s] control or custody or within [its] means to produce.”

From the record it appears the subpoena was never actually served on the bank.4 In any event, before the *495return date, USSF and two of its members brought this action to enjoin implementation of the subpoena duces tecum.

The complaint named as defendants Chairman East-land, nine other Senators, the Chief Counsel to the Subcommittee, and the bank.5 The complaint charged that the authorizing resolutions and the Subcommittee’s actions implementing them were an unconstitutional abuse of the legislative power of inquiry, that the “sole purpose” of the Subcommittee investigation was to force “public disclosure of beliefs, opinions, expressions and associations of private citizens which may be unorthodox or unpopular,” and that the “sole purpose” of the subpoena was to “harass, chill, punish and deter [USSF and its members] in their exercise of their rights and duties under the First Amendment and particularly to stifle the freedom of the press and association guaranteed by that amendment.”6 The subpoena was issued to the bank rather than to USSF and its members, the complaint claimed, “in order to deprive [them] of their rights to protect their private records, such as the sources of their contributions, as they would be entitled to do if the subpoenas had been issued against them directly.” The complaint further claimed that financial support to *496USSF is obtained exclusively through contributions from private individuals, and if the bank records are disclosed “much of that financial support will be withdrawn and USSF will be unable to continue its constitutionally protected activities.”7

For relief USSF and its members, the respondents, sought a permanent injunction restraining the Members of the Subcommittee and its Chief Counsel from trying to enforce the subpoena by contempt of Congress or other means and restraining the bank from complying with the subpoena.8 Respondents also sought a declaratory judgment declaring the subpoena and the Senate resolutions void under the Constitution. No damages claim was made.

Since the return date on the subpoena was June 4, 1970, three days after the action was begun, enforcement of the subpoena was stayed 9 in order to avoid mootness and to prevent possible irreparable injury. The District Court then held hearings and took testimony on the matter. That court ultimately held 10 that respondents *497had not made a sufficient showing of irreparable injury to warrant an injunction. The court also purported to strike a balance between the legislative interest and respondents’ asserted First Amendment rights, NAACP v. Alabama, 357 U. S. 449 (1958). It concluded that a valid legislative purpose existed for the inquiry because Congress was pursuing its functions, under Art. I, §8, of raising and supporting an army, and had a legitimate interest in “scrutinizing] closely possible infiltration of subversive elements into an organization which directly affects the armed forces of this country.”11 Relying on Barenblatt v. United States, 360 U. S. 109 (1959), the District Court concluded that the legislative interest must prevail over respondents’ asserted rights, and denied respondents’ motions for preliminary and permanent injunctions. It also dismissed as to the petitioner Senators after concluding that the Speech or Debate Clause immunizes them from suit. Dombrowski v. Eastland, 387 U. S. 82 (1967).

The Court of Appeals reversed, holding first that, although courts should hesitate to interfere with congressional actions even where First Amendment rights clearly are implicated, such restraint could not preclude judicial review where no alternative avenue of relief is available other than “through the equitable powers of the court.” 159 U. S. App. D. C. 352, 359, 488 F. 2d 1252, 1259 (1973). Here the subpoena was directed to a third party which could not be expected to refuse *498compliance; unless respondents could obtain judicial relief the bank might comply, the case would become moot, and the asserted violation of respondents’ constitutional rights would be irreparable. Because the subpoena was not directed to respondents, the Court of Appeals noted, the traditional route for raising their defenses by refusing compliance and testing the legal issues in a contempt proceeding was not available to them. Ansara v. Eastland, 143 U. S. App. D. C. 29, 442 F. 2d 751 (1971).

Second, the Court of Appeals concluded that if the subpoena were obeyed respondents’ First Amendment rights would be violated. The court said:

“The right of voluntary associations, especially those engaged in activities which may not meet with popular favor, to be free from having either state or federal officials expose their affiliation and membership absent a compelling state or federal purpose has been made clear a number of times. See NAACP v. Alabama, 357 U. S. 449; Bates v. Little Rock, 361 U. S. 516; Louisiana ex rel. Gremillion v. NAACP, 366 U. S. 293 (1961); Gibson v. Florida Legislative Committee, 372 U. S. 539 (1962); Pollard v. Roberts, 393 U. S. 14 (1968), affirming the judgment of the three-judge district court for the Eastern District of Arkansas, 283 F. Supp. 248 (1968).” 159 U. S. App. D. C., at 364, 488 F. 2d, at 1264.

In this case that right would be violated, the Court of Appeals held, because discovery of the identities of donors was the admitted goal of the subpoena, id., at 367, .488 F. 2d, at 1267, and that information could be gained as easily from bank records as from membership lists. Moreover, if donors’ identities were revealed, or if donors reasonably feared that result, USSF’s contributions would *499decrease substantially, as had already occurred merely because of the threat posed by the subpoena.12

The Court of Appeals then fashioned a remedy to deal with the supposed violation of rights. It ordered the District Court to “consider the extent to which committee counsel should properly be required to give evidence as to matters without the ‘legislative sphere.’ ” Id., at 370, 488 F. 2d, at 1270.13 It also ordered that the court should “be liberal in granting the right of amendment” to respondents to add other parties if thereby “the case can better proceed to a decision on the validity of the subpoena.” Ibid. Members of Congress could be added as parties, the Court of Appeals said, if their presence is “unavoidable if a valid order is to be entered by the court to vindicate rights which would otherwise go unredressed.” Ibid. The Court of Appeals concluded that *500declaratory relief against Members is “preferable” to “any coercive order.” Ibid. The clear implication is that the District Court was authorized to enter a “coercive order” which in context could mean that the Subcommittee could be prevented from pursuing its inquiry by use of a subpoena to the bank.

One judge dissented on the ground that the membership-list cases were distinguishable because in none of them was there a “showing that the lists were requested for a proper purpose.” Id., at 377, 488 F. 2d, at 1277. Here, on the other hand, the dissenting judge concluded, “there is a demonstrable relationship between the information sought and the valid legislative interest of the federal Congress” in discovering whether any money for USSF activities “came from foreign sources or subversive organizations,” id., at 377, 378, 488 F. 2d, at 1277, 1278; whether USSF activities may have constituted violations of 18 U. S. C. § 2387 (a), which prohibits interference with the loyalty, discipline, or morale of the Armed Services; or whether the anonymity of USSF donors might have disguised persons who had not complied with the Foreign Agents Registration Act of 1938, 22 U. S. C. § 611 et seq. Finally, he noted that the prime purpose of the Subcommittee’s inquiry was to investigate application of the Internal Security Act of 1950, 50 U. S. C. § 781 et seq., and that, too, provided a legitimate congressional interest.

The dissenting judge then balanced the congressional interests against private rights, Barenblatt v. United States, supra; Watkins v. United States, 354 U. S. 178, 198 (1957), and struck the balance in favor of the investigative role of Congress. He reasoned that there is no right to secrecy which can frustrate a legitimate congressional inquiry into an area where legislation may be had. 159 U. S. App. D. C., at 378-379, 382, 488 F. 2d, at 1278-*5011279, 1282. Absent a showing that the information sought could not be used in the legislative sphere, he concluded, judicial interference was unwarranted.

We conclude that the actions of the Senate Subcommittee, the individual Senators, and the Chief Counsel are protected by the Speech or Debate Clause of the Constitution, Art. I, § 6, el. 1, and are therefore immune from judicial interference. We reverse.

II

The question14 to be resolved is whether the actions of the petitioners fall within the “sphere of legitimate legislative activity.” If they do, the petitioners “shall not be questioned in any other Place” about those activities since the prohibitions of the Speech or Debate Clause are absolute, Doe v. McMillan, 412 U. S. 306, 312-313 (1973); United States v. Brewster, 408 U. S. 501, 516 (1972); Gravel v. United States, 408 U. S. 606, 623 n. 14 (1972); Powell v. McCormack, 395 U. S. 486, 502-503 (1969); Dombrowski v. Eastland, 387 U. S., at 84-85; United States v. Johnson, 383 U. S. 169, 184-185 (1966); Barr v. Matteo, 360 U. S. 564, 569 (1959).

Without exception, our cases have read the Speech or Debate Clause broadly to effectuate its purposes. Kil*502bourn v. Thompson, 103 U. S. 168, 204 (1881); United States v. Johnson, supra, at 179; Powell v. McCormack, supra, at 502-503; United States v. Brewster, supra, at 508-509; Gravel v. United States, supra, at 617-618; cf. Tenney v. Brandhove, 341 U. S. 367, 376-378 (1951). The purpose of the Clause is to insure that the legislative function the Constitution allocates to Congress may be performed independently.

“The immunities of the Speech or Debate Clause were not written into the Constitution simply for the personal or private benefit of Members of Congress, but to protect the integrity of the legislative process by insuring the independence of individual legislators.” United States v. Brewster, supra, at 507.

In our system “the clause serves the additional function of reinforcing the separation of powers so deliberately established by the Founders.” United States v. Johnson, supra, at 178.

The Clause is a product of the English experience. Kilbourn v. Thompson, supra; United States v. Johnson, supra, at 177-179. Due to that heritage our cases make it clear that the “central role” of the Clause is to “prevent intimidation of legislators by the Executive and accountability before a possibly hostile judiciary, United States v. Johnson, 383 U. S. 169, 181 (1966),” Gravel v. United States, supra, at 617. That role is not the sole function of the Clause, however, and English history does not totally define the reach of the Clause. Rather, it “must be interpreted in light of the American experience, and in the context of the American constitutional scheme of government . . . .” United States v. Brewster, supra, at 508. Thus we have long held that, when it applies, the Clause provides protection against civil as well as criminal actions, and against actions brought by private indi*503viduals as well as those initiated by the Executive Branch. Kilbourn v. Thompson, supra; Tenney v. Brandhove, supra; Doe v. McMillan, supra; Dombrowski v. Eastland, supra.

The applicability of the Clause to private civil actions is supported by the absoluteness of the term “shall not be questioned,” and the sweep of the term “in any other Place.” In reading the Clause broadly we have said that legislators acting within the sphere of legitimate legislative activity “should be protected not only from the consequences of litigation’s results but also from the burden of defending themselves.” Dombrowski v. Eastland, supra, at 85. Just as a criminal prosecution infringes upon the independence which the Clause is designed to preserve, a private civil action, whether for an injunction or damages, creates a distraction and forces Members to divert their time, energy, and attention from their legislative tasks to defend the litigation. Private civil actions also may be used to delay and disrupt the legislative function. Moreover, whether a criminal action is instituted by the Executive Branch, or a civil action is brought by private parties, judicial power is still brought to bear on Members of Congress and legislative independence is imperiled. We reaffirm that once it is determined that Members are acting within the “legitimate legislative sphere” the Speech or Debate Clause is an absolute bar to interference. Doe v. McMillan, 412 U. S., at 314.

Ill

In determining whether particular activities other than literal speech or debate fall within the “legitimate legislative sphere” we look to see whether the activities took place “in a session of the House by one of its members in relation to the business before it.” Kilbourn v. *504Thompson, 103 U. S., at 204. More specifically, we must determine whether the activities are

“an integral part of the deliberative and communicative processes by which Members participate in committee and House proceedings with respect to the consideration and passage or rejection of proposed legislation or with respect to other matters which the Constitution places within the jurisdiction of either House.” Gravel v. United States, 408 U. S., at 625.

See Doe v. McMillan, supra, at 313.

The power to investigate and to do so through compulsory process plainly falls within that definition. This Court has often noted that the power to investigate is inherent in the power to make laws because “[a] legislative body cannot legislate wisely or effectively in the absence of information respecting the conditions which the legislation is intended to affect or change.” McGrain v. Daugherty, 273 U. S. 135, 175 (1927). See Anderson v. Dunn, 6 Wheat. 204 (1821); United States v. Rumely, 345 U. S. 41, 46 (1953).15 Issuance of subpoenas such as the one in question here has long been held to be a legitimate use by Congress of its power to investigate. Watkins v. United States, 354 U. S., at 188.

“[W]here the legislative body does not itself possess *505the requisite information — which not infrequently is true — recourse must be had to others who do possess it. Experience has taught that mere requests for such information often are unavailing, and also that information which is volunteered is not always accurate or complete; so some means of compulsion are essential to obtain what is needed.” McGrain v. Daugherty, supra, at 175.

It also has been held that the subpoena power may be exercised by a committee acting, as here, on behalf of one of the Houses. Id., at 158. Cf. Tenney v. Brandhove, 341 U. S., at 377-378. Without such power the Subcommittee may not be able to do the task assigned to it by Congress. To conclude that the power of inquiry is other than an integral part of the legislative process would be a miserly reading of the Speech or Debate Clause in derogation of the ‘'integrity of the legislative process.” United States v. Brewster, 408 U. S., at 524; and United States v. Johnson, 383 U. S., at 172.

We have already held that the act “of authorizing an investigation pursuant to which . . . materials were gathered” is an integral part of the legislative process. Doe v. McMillan, 412 U. S., at 313. The issuance of a subpoena pursuant to an authorized investigation is similarly an indispensable ingredient of lawmaking; without it our recognition that the act “of authorizing” is protected would be meaningless. To hold that Members of Congress are protected for authorizing an investigation, but not for issuing a subpoena in exercise of that authorization, would be a contradiction denigrating the power granted to Congress in Art. I and would indirectly impair the deliberations of Congress. Gravel, supra, at 625.

The' particular investigation at issue here is related to and in furtherance of a legitimate task of Congress. *506Watkins v. United States, 354 U. S., at 187. On this record the pleadings show that the actions of the Members and the Chief Counsel fall within the “sphere of legitimate legislative activity.” The Subcommittee was acting under an unambiguous resolution from the Senate authorizing it to make a complete study of the “administration, operation, and enforcement of the Internal Security Act of 1950 . ...” S. Res. 341, 91st Cong., 2d Sess. (1970). That grant of authority is sufficient to show that the investigation upon which the Subcommittee had embarked concerned a subject on which “legislation could be had.” McGrain v. Daugherty, 273 U. S., at 177; see Communist Party v. Control Board, 367 U. S. 1 (1961).

The propriety of making USSF a subject of the investigation and subpoena is a subject on which the scope of our inquiry is narrow. Hutcheson v. United States, 369 U. S. 599, 618-619 (1962). See Sinclair v. United States, 279 U. S. 263, 294-295 (1929). “The courts should not go beyond the narrow confines of determining that a committee’s inquiry may fairly be deemed within its province.” Tenney v. Brandhove, supra, at 378. Cf. Doe v. McMillan, 412 U. S., at 316 n. 10. Even the most cursory look at the facts presented by the pleadings reveals the legitimacy of the USSF subpoena. Inquiry into the sources of funds used to carry on activities suspected by a subcommittee of Congress to have a potential for undermining the morale of the Armed Forces is within the legitimate legislative sphere. Indeed, the complaint here tells us that USSF operated on or near military and naval bases, and that its facilities became the “focus of dissent” to declared national policy. Whether USSF activities violated any statute is not relevant; the inquiry was intended to inform Congress in an area where legislation may be had. USSF asserted it *507does not know the sources of its funds; in light of the Senate authorization to the Subcommittee to investigate “infiltration by persons who are or may be under the domination of... foreign government,” supra, at 493, and in view of the pleaded facts, it is clear that the subpoena to discover USSF’s bank records “may fairly be deemed within [the Subcommittee’s] province.” Tenney v. Brandhove, supra, at 378.

We conclude that the Speech or Debate Clause provides complete immunity for the Members for issuance of this subpoena. We draw no distinction between the Members and the Chief Counsel. In Gravel, supra, we made it clear that “the day-to-day work of such aides is so critical to the Members’ performance that they must be treated as [the Members’] alter egos ....” 408 U. S., at 616-617. See also id., at 621. Here the complaint alleges that the “Subcommittee members and staff caused the . . . subpoena to be issued . . . under the authority of Senate Resolution 366 . . . .” The complaint thus does not distinguish between the activities of the Members and those of the Chief Counsel. Contrast, Dombrowski v. Eastland, 387 U. S., at 84. Since the Members are immune because the issuance of the subpoena is “essential to legislating,” their aides share that immunity. Gravel v. United States, 408 U. S., at 621; Doe v. McMillan, 412 U. S., at 317.

IV

Respondents rely on language in Gravel v. United States, supra, at 621:

“[N]o prior case has held that Members of Congress would be immune if they executed an invalid resolution by themselves carrying out an illegal arrest, or if, in order to secure information for a hearing, themselves seized the property or invaded *508the privacy of a citizen. Neither they nor their aides should be immune from liability or questioning in such circumstances.”

From this respondents argue that the subpoena works an invasion of their privacy, and thus cannot be immune from judicial questioning. The conclusion is unwarranted. The quoted language from Gravel referred to actions which were not “essential to legislating.” Ibid. See United States v. Johnson, 383 U. S. 169 (1966). For example, the arrest by the Sergeant at Arms was held unprotected in Kilbourn v. Thompson, supra, because it was not “essential to legislating.” See Marshall v. Gordon, 243 U. S. 521, 537 (1917). Quite the contrary is the case with a routine subpoena intended to gather information about a subject on which legislation may be had. See Quinn v. United States, 349 U. S. 155, 161 (1955).

Respondents also contend that the subpoena cannot be protected by the speech or debate immunity because the “sole purpose” of the investigation is to force “public disclosure of beliefs, opinions, expressions and associations of private citizens which may be unorthodox or unpopular.” App. 16. Respondents view the scope of the privilege too narrowly. Our cases make clear that in determining the legitimacy of a congressional act we do not look to the motives alleged to have prompted it. Watkins v. United States, 354 U. S., at 200; Hutcheson v. United States, 369 U. S., at 614. In Brewster, we said that “the Speech or Debate Clause protects against inquiry into acts that occur in the regular course of the legislative process and into the motivation for those acts.” 408 U. S., at 525 (emphasis added). And in Tenney v. Brandhove we said that “[t]he claim of an unworthy purpose does not destroy the privilege.” 341 U. S., at 377. If the mere allegation that a valid legis*509lative act was undertaken for an unworthy purpose would lift the protection of the Clause, then the Clause simply would not provide the protection historically undergirding it. “In times of political passion, dishonest or vindictive motives are readily attributed to legislative conduct and as readily believed.” Id., at 378. The wisdom of congressional approach or methodology is not open to judicial veto. Doe v. McMillan, 412 U. S., at 313. Nor is the legitimacy of a congressional inquiry to be defined by what it produces. The very nature of the investigative function — like any research — is that it takes the searchers up some “blind alleys” and into nonproductive enterprises. To be a valid legislative inquiry there need be no predictable end result.

Finally, respondents argue that the purpose of the subpoena was to “harass, chill, punish and deter” them in the exercise of their First Amendment rights, App. 16, and thus that the subpoena cannot be protected by the Clause. Their theory seems to be that once it is alleged that First Amendment rights may be infringed by congressional action the Judiciary may intervene to protect those rights; the Court of Appeals seems to have subscribed to that theory. That approach, however, ignores the absolute nature of the speech or debate protection16 *510and our cases which have broadly construed that protection.

“Congressmen and their aides are immune from liability for their actions within the ‘legislative sphere/ Gravel v. United States, supra, at 624-625, even though their conduct, if performed in other than legislative contexts, would in itself be unconstitutional or otherwise contrary to criminal or civil statutes.” Doe v. McMillan, 412 U. S., at 312-313.

For us to read the Clause as respondents suggest would create an exception not warranted by the language, purposes, or history of the Clause. Respondents make the familiar argument that the broad protection granted by the Clause creates a potential for abuse. That is correct, and in Brewster, supra, we noted that the risk of such abuse was “the conscious choice of the Framers” buttressed and justified by history. 408 U. S., at 516. Our consistently broad construction of the Speech or *511Debate Clause rests on the belief that it must be so construed to provide the independence which is its central purpose.

This case illustrates vividly the harm that judicial interference may cause. A legislative inquiry has been frustrated for nearly five years, during which the Members and their aide have been obliged to devote time to consultation with their counsel concerning the litigation, and have been distracted from the purpose of their inquiry. The Clause was written to prevent the need to be confronted by such "questioning” and to forbid invocation of judicial power to challenge the wisdom of Congress’ use of its investigative authority.17

V

When the Senate case was in the Court of Appeals it was consolidated with three other cases18 because it was assumed that “a decision in [the Senate] case might well control the disposition of [the others].” Those cases *512involved subpoenas from the House Internal Security Committee to banks for the bank records of certain organizations. As in the Senate aspect of this case, the organizations whose bank records were sought sued, alleging that if the subpoenas were honored their constitutional rights would be violated. The issue of speech or debate protection for Members and aides is presented in all the cases consolidated in the Court of Appeals. However, the complaints in the House cases are different from the complaint in the Senate case, additional parties are involved, and consequently additional issues may be presented.

Progress in the House cases was suspended when they were in the pleading stage awaiting the outcome of the Senate aspect of this case. The issues in them, therefore, have not been joined. Additionally, it appears that the Session in which the House subpoenas were issued has expired. Since the House, unlike the Senate, is not a continuing body, McGrain v. Daugherty, 273 U. S., at 181; Gojack v. United States, 384 U. S. 702, 706-707, n. 4 (1966), a question of mootness may be raised. Moreover it appears that the Committee that issued the subpoenas has been abolished by the House, H. Res. 5, 94th Cong., 1st Sess., Jan. 14, 1975. In view of these problems, and because the House aspects of this case were not briefed or argued here, we conclude it would be unwise to attempt to decide any issues they might present that are not resolved in the Senate aspect of this case. Powell v. McCormack, 395 U. S., at 496 n. 8; id., at 559 (Stewart, J., dissenting).

. Judgment with respect to the Senate aspect of this .case is reversed and the case is remanded to the Court of Appeals for entry of a judgment directing the District Court to dismiss the complaint. The House aspects of this case are remanded with directions to remand to *513the District Court for further consideration consistent with this opinion.

Reversed and remanded.

1

USSF is, or has been, listed with .the Internal Revenue Service as a tax-exempt charitable organization.

2

According to the complaint filed in this action USSF has helped provide civilian legal defense for military personnel, and books, newspapers, and library material on request. App. 11.

3

Ibid.

4

The subpoena at issue here directed “Any U. S. Marshal” to serve and return, but there is no proof of service in the record. The *495Subcommittee had issued two previous subpoenas duces tecum to the bank, but they had been withdrawn because of procedural problems. Apparently, at least one of those subpoenas actually was served on the bank. Id., at 13. The other subpoena also may have been served because the bank informed respondents of its existence. Id., at 14'. Respondents claim all three subpoenas are substantially identical.

5

Apparently, at least partially because the bank was never served, Tr. of Oral Arg. 22, 46, it has not participated in the action. Id., at 15, 19-20, 21-22. Therefore, as the case reaches us only the Senators and the Chief Counsel are active participants.

6

App. 16.

7

Id., at 17-18.

8

Id., at 18.

9

On June 1, the District Court refused to enter a temporary restraining order, but on June 4 the Court of Appeals stayed enforcement of the subpoena pending expedited consideration of the matter by the District Court. The Court of Appeals reasoned that the threat of irreparable injury if the subpoena were honored, and the significance of the issues involved, necessitated “the kind of consid.eration and deliberation that would be provided by ... a hearing on an application for injunction.” Id., at 22. One judge dissented.

10

After the Court of Appeals stayed enforcement of the subpoena the District Court held an expedited hearing on respondents’ motion for a preliminary injunction and petitioners’ motion to dismiss. Afterwards the District Court denied both motions; however, the Court of Appeals again stayed enforcement of the subpoena pending further order. At that time the Court of Appeals ordered the District Court to proceed to final judgment on the merits, with a *497view to consolidating any appeal from that judgment with the appeal on the denial of a preliminary injunction. The District Court then took testimony on the merits and, finally, denied respondents’ motion for a permanent injunction against the subpoena. Appeal from that decision apparently was consolidated with the appeal from the denial of the preliminary injunction.,

11

Id., at 31.

12

It appears that the District Court finding of failure to show irreparable injury was held clearly erroneous. 159 U. S. App. D. C. 352, 367, 488 F. 2d 1252, 1267 (1973). See Fed. Rule Civ. Proc. 52 (a).

13

Respondents had made a motion in the District Court to compel petitioner Sourwine, the subcommittee counsel, to give testimony. The Senate passed a resolution; S. Res. 478, 91st Cong., 2d Sess., Oct. 13, 1970, authorizing Sourwine to testify only as to matters of public record. Respondents moved to compel further testimony from Sourwine, but the District Court denied the motion. The court ruled Sourwine’s' information “has been received by him pursuant to his official duties as a staff employee of the Senate . . . [and as] such, the information is within the privilege of the Senate . , . Senate Rule SOI, Senate Manual, Senate Document No. 1 of the 90th Congress, First Session.” App. 38. The court also ruled that the Senate made a timely and appropriate invocation of its privilege. Thus information held by Sourwine was not discoverable. Fed. Rule Civ. Proc. 26(b)(1). Respondents’ appeal from this ruling was heard by the Court of Appeals with their appeals from the denial of injunctive relief. 159 U. S. App. D. C., at 358, 488 F. 2d, at 1258.

14

On this record the Court of Appeals correctly held that the District Court properly entertained this action initially. 159 U. S. App. D. C., at 359-360, 488 F. 2d, at 1259-1260. The Court of Appeals saw a significant difference between a subpoena that seeks information directly from a party and one that seeks the same information from a third person. In the former case the party can resist and thereby test the subpoena; in the latter case, however, unless a court may inquire to determine whether a legitimate legislative purpose is present, Doe v. McMillan, 412 U. S. 306, 312-313 (1973); Gravel v. United States, 408 U. S. 606, 624 (1972); Tenney v. Brandhove, 341 U. S. 367, 376 (1951), compliance by the third person could frustrate any judicial inquiry.

15

Although the power to investigate is necessarily broad it is not unlimited. Its boundaries are defined by its source. Watkins v. United States, 354 U. S. 178, 197 (1957). Thus, “[t]he scope of the power of inquiry ... is as penetrating and far-reaching as the potential power to enact and appropriate under the Constitution.” Barenblatt v. United States, 360 U. S. 109, 111 (1959); Sinclair v. United States, 279 U. S. 263, 291-292 (1929). We have made it clear, however, that Congress is not invested with a “ ‘general’ power to inquire into private affairs.” McGrain v. Daugherty, 273 U. S. 135, 173 (1927). The subject of any inquiry always must be one “on which legislation could be had.” Id., at 177.

16

In some situations we have balanced First Amendment rights against public interests, Watkins v. United States, 354 U. S. 178 (1957); Barenblatt v. United States, 360 U. S. 109 (1959), but those cases did not involve attempts by private parties to impede congressional action where the Speech or Debate Clause was raised by Congress by way of- defense. Cf. United States v. Rumely, 345 U. S. 41, 46 (1953). The cases were criminal prosecutions where defendants sought to justify their refusals to answer congressional inquiries by asserting their First Amendment rights. Different problems were presented from those here. Any interference with congressional action had already occurred when the cases reached us, and Congress was seeking the aid of the Judiciary to enforce its will. Our task was to perform the judicial function in criminal prosecu*510tions, and we properly scrutinized the predicates of the criminal prosecutions. Watkins, supra, at 208; Flaxer v. United States, 358 U. S. 147, 151 (1958); Quinn v. United States, 349 U. S. 155, 162, 169 (1955); Hutcheson v. United States, 369 U. S. 599, 630-631 (1962) (Warren, C. J., dissenting); 640 (Douglas, J., dissenting). As Mr. Justice Frankfurter said concurring in Watkins:

“By . . . making the federal judiciary the affirmative agency for enforcing the authority that underlies the congressional power to punish for contempt, Congress necessarEy brings into play the specific provisions of the Constitution relating to the prosecution of offenses and those implied restrictions under which courts function.” 354 U. S., at 216.

Where we are presented with an attempt to interfere with an ongoing activity by Congress, and that activity is found to be within the legitimate legislative sphere, balancing plays no part. The speech or debate protection provides an absolute immunity from judicial interference. Collateral harm which may occur in the course of a legitimate legislative inquiry does not allow us to force the inquiry to “grind to a halt.” Hutcheson v. United States, supra, at 618.

17

Although the Speech or Debate Clause has never been read so broadly that legislators are “absolved of the responsibility of filing a motion to dismiss,” Powell v. McCormack, 395 U. S. 486, 505 n. 25 (1969); see Tenney v. Brandhove, 341 U. S., at 376-377, the purposes which the Clause serves require that such motions be given the most expeditious treatment by district courts because one branch of Government is being asked to halt the functions of a coordinate branch. If there is a dismissal and an appeal, courts of appeals have a duty to see that the litigation is swiftly resolved. Enforcement of the Subcommittee’s subpoena has been restrained since June 1970, nearly five years, while this litigation dragged through the courts. This protracted delay has frustrated a valid congressional inquiry.

18

Progressive Labor Party v. Committee on Internal Security of the U. S. House of Representatives (C. A. No. 71-1609); National Peace Action Coalition v. Committee on Internal Security of the U. S. Home of Representatives (C. A. No. 71-1693); Peoples Coalition for Peace and Jmtice v. Committee on Internal Security of the U. S. Home of Representatives (C. A. No. 71-1717).

Mr. Justice Marshall,

with whom Mr. Justice Brennan and Mr. Justice Stewart join, concurring in the judgment.

I agree with the Court that the Speech or Debate Clause protects the actions of the Senate petitioners in this case from judicial interference, and that the House aspects of this case should be reconsidered by the District Court. As our cases have consistently held, however, the Speech or Debate Clause protects legislators and their confidential aides from suit; it does not immunize congressional action from judicial review. I write today only to emphasize that- the Speech or Debate Clause does not entirely immunize a congressional subpoena from challenge by a party not in a position to assert his constitutional rights by refusing to comply with it.

I

When the Senate Subcommittee on Internal Security subpoenaed the records of the bank account of respondent USSF (hereinafter respondent), respondent brought this suit in the District of Columbia against the Members of the Subcommittee, its counsel, and the bank to declare invalid and restrain enforcement of the subpoena. Suit was brought in the District of Columbia because the Court of Appeals for the Second Circuit had held one week before in a suit against the same Subcommittee and its counsel that jurisdiction and venue lay only in the District of Columbia. Liberation News Service v. Eastland, 426 F. 2d 1379 (1970). Having sued in the District of Columbia, however, respondent found that it could not get proper service on the New York *514bank. Consequently, the only parties that it brought before the courts were the Senators and their counsel.

As the Court points out, the District Court properly entertained the action in order to provide a forum in which respondent could assert its constitutional objections to the subpoena, since a neutral third party could not be expected to resist the subpoena by placing itself in contempt. Ante, at 501 n. 14; see Perlman v. United States, 247 U. S. 7, 12 (1918); United States v. Doe, 455 F. 2d 753, 756-757 (CA1), vacated sub nom. Gravel v. United States, 408 U. S. 606 (1972); see also United States v. Nixon, 418 U. S. 683, 691 (1974). But a court’s inquiry in such a setting is necessarily quite limited once defendants entitled to do so invoke the privilege of the Speech or Debate Clause, as was done here. If the Senators’ actions were within the “legitimate legislative, sphere,” the matter ends there and they are answerable no further to the court. If their counsel’s actions were in aid of that activity, then as a confidential employee of the Members, he is equally shielded from further judicial interference. Compare Gravel v. United States, supra, at 616-622, with Doe v. McMillan, 412 U. S. 306, 314-316 (1973).1

*515The Court applies this well-settled doctrine to the present case and holds that since the issuance of the subpoena fell within the sphere of legitimate legislative activity, the proceedings against the petitioners must come to an end. I do not read the Court to suggest, however, nor could I agree, that the constitutionality of a congressional subpoena is always shielded from more searching judicial inquiry. For, as the very cases on which the Court relies demonstrate, the protection of the Speech or Debate Clause is personal. It extends to Members and their counsel acting in a legislative capacity; it does not preclude judicial review of their decisions in an appropriate case, whether they take the form of legislation or a subpoena.

II

Modern legislatures, and particularly the Congress, may legislate on a wide range of subjects. In order to discharge this function, and their related informing function, they may genuinely need á great deal of information in the exclusive possession of persons who would not make it available except under the compulsion of a subpoena. When duly subpoenaed, however, such a person does not shed his constitutional right to withhold certain classes of information. If he refuses to testify or to produce documents and invokes a pertinent privilege, he still runs the risk that the legislature will cite' him for contempt.2 At trial he may defend on the basis of the constitutional right to withhold information from the legislature, and his right will be respected *516along with the legitimate needs of the legislature. As the Court said in Watkins v. United States, 354 U. S. 178, 188 (1957):

“The Bill of Rights is applicable to [congressional] investigations as to all forms of governmental action. Witnesses cannot be compelled to give evidence against themselves. They cannot be subjected to unreasonable search and seizure. Nor can the First Amendment freedoms of speech, press, religion, or political belief and association be abridged.”

Accord. Gibson v. Florida Legislative Investigation Committee, 372 U. S. 539 (1963); see Quinn v. United States, 349 U. S. 155, 161 (1955); Reinstein & Silverglate, Legislative Privilege and the Separation of Powers, 86 Harv. L. Rev. 1113, 1173-1176 (1973).

The Speech or Debate Clause ■ cannot be used to avoid meaningful review of constitutional objections to a subpoena simply because the subpoena is served on a third party. Our prior cases arising under the Speech or Debate Clause indicate only that a Member of Congress or his aide may not be called upon to defend a subpoena against constitutional objection, and not that the objection will not be heard at all.

The privilege of the Speech or Debate Clause extends to Members of Congress when their action is “essential to legislating,” in order to assure the independence of the legislators and their freedom from vexatious and distracting litigation. See United States v. Johnson, 383 U. S. 169, 180-182 (1966); United States v. Brewster, 408 U. S. 501, 512 (1972). Further, “a Member and his aide are to be 'treated as one’ ” under the Clause, “insofar as the conduct of the latter would be a protected legislative act if performed by the Member himself.” Gravel v. United States, 408 U. S., at 616, 618. At the same time, however, the Speech or Debate Clause does not insulate *517legislative functionaries carrying out nonlegislative tasks. Doe v. McMillan, 412 U. S., at 315.

Kilbourn v. Thompson, 103 U. S. 168 (1881), was an action to recover damages for false imprisonment. The Court held that the Speech or Debate Clause afforded the defendant Members of Congress a good defense since they had taken no part in Kilbourn’s arrest other than to vote that the Sergeant at Arms accomplish it. The Sergeant at Arms, however, was held to answer for carrying out their unconstitutional directive; and Kilbourn later recovered $20,000 from him. See Kilbourn v. Thompson, MacArth. & M. 401, 432 (Sup. Ct. D. C. 1883). The basis for the Court’s holding was not, however, as the Court seems at one point to suggest, ante, at 508, that the arrest was inessential to legislating. We have already twice observed that the “resolution authorizing Kilbourn’s arrest . . . was clearly legislative in nature. But the resolution was subject to judicial review insofar as its execution impinged on a citizen's rights as it did there. That the House could with impunity order an unconstitutional arrest afforded no protection for those who made the arrest.” Gravel, supra, at 618 (emphasis added); Doe v. McMillan, supra, at 315 n. 9.

This case does not present the questions of what would be the proper procedure, and who might be the proper parties defendant, in an effort to get before a court a constitutional challenge to a subpoena duces tecum issued to a third party.3 As respondent’s counsel conceded at oral argument, this case is at an end if the Senate peti*518tioners are upheld in their claim of immunity, as they must be.4

1

Dombrowski v. Eastland, 387 U. S. 82 (1967), was a damages action against the same Chairman and Counsel Sourwine of the Senate Subcommittee on Internal Security, based on allegations of a conspiracy with state officials to violate the plaintiff’s Fourth Amendment rights. The Court distinguished between the Senator and counsel, remanding only the case involving the latter for trial because there was disputed evidence in the record giving “more than merely colorable substance” to the claims against him, id., at 84; the record contained no evidence of the Senator’s involvement in any activity that could give rise to liability. The Court noted that the doctrine of immunity for acts within the legislative sphere is “less absolute, although applicable, when applied to officers or employees of a legislative body, rather than to legislators themselves.” Id., at 85. In the present case, where counsel is alleged *515only to have joined with the Senators in causing the subpoena to be issued, we have no occasion to distinguish between Mr. Sourwine and the Senators.

2

In the federal system, this is done by the appropriate chamber referring the matter to the United States Attorney for presentation to a grand jury, indictment, and trial in the federal courts. See 2 U. S. C. §§ 192-194.

3

See the opinion below, 159 U. S. App. D. C. 352, 370, 488 F. 2d 1252, 1270 (1973); Liberation News Service v. Eastland, 426 F. 2d 1379, 1384 n. 10 (CA2 1970); cf. Stamler v. Willis, 415 F. 2d 1365, 1369 (CA7 1969).

4

In the House aspects of this case, where the banks to which the subpoenas were directed are within the jurisdiction of the District Court, this would not necessarily be true if that court were to determine that the issues are not moot.

Me. Justice Douglas,

dissenting.

I would affirm the judgment below.

The basic issues in this case were canvassed by me in Tenney v. Brandhove, 341 U. S. 367, 381-383 (1951) (dissenting opinion), and by the Court in Dombrowski v. Eastland, 387 U. S. 82 (1967), in an opinion which I joined.. Under our federal regime that delegates, by the Constitution and Acts of Congress, awesome powers to individuals, those powers may not be used to deprive people of their First Amendment or other constitutional rights. It is my view that no official, no matter how high or majestic his or her office, who is within the reach of judicial process, may invoke immunity for his actions for which wrongdoers normally suffer. There may be few occasions when, on the merits, it w;ould be appropriate to invoke such a remedy. But no regime of law that can rightfully claim that name may make trustees of these vast powers immune from actions brought by people who have been wronged by official action. See Watkins v. United States, 354 U. S. 178, 198 (1957).

NIXON v. UNITED STATES et al.

No. 91-740.

Argued October 14, 1992

Decided January 13, 1993

*225Rehnquist, C. J., delivered the opinion of the Court, in which Stevens, O’Connor, Scalia, Kennedy, and Thomas, JJ., joined. Stevens, J., filed a concurring opinion, post, p. 238. White, J., filed an opinion concurring in the judgment, in which Blackmun, J., joined, post, p. 239. Souter, J., filed an opinion concurring in the judgment, post, p. 262.

David Overlook Stewart argued the cause for petitioner. With him on the briefs were Peter M. Brody, Thomas B. Smith, Boyce Holleman, and Michael B. Holleman.

*226Solicitor General Starr argued the cause for respondents. With him on the brief were Assistant Attorney General Ger-son, Deputy Solicitor General Roberts, Jeffrey R Minear, Douglas Letter, Michael Davidson, Ken U. Benjamin, Jr., Morgan J Frankel, and Claire M. Sylvia.*

*

Patti A Goldman and Alan B. Morrison filed a brief for Public Citizen as amicus curiae urging reversal.

Joseph P. Galda, Daniel J. Popeo, and Paul D. Kamenar filed a brief for the Washington Legal Foundation et al. as amici curiae urging affirmance.

CHIEF Justice Rehnquist

delivered the opinion of the Court.

Petitioner Walter L. Nixon, Jr., asks this Court to decide whether Senate Rule XI, which allows a committee of Senators to hear evidence against an individual who has been impeached and to report that evidence to the full Senate, violates the Impeachment Trial Clause, Art. I, §3, cl. 6. That Clause provides that the “Senate shall have the sole Power to try all Impeachments.” But before we reach the merits of such a claim, we must decide whether it is “justicia-ble,” that is, whether it is a claim that may be resolved by the courts. We conclude that it is not.

Nixon, a former Chief Judge of the United States District Court for the Southern District of Mississippi, was convicted by a jury of two counts of making false statements before a federal grand jury and sentenced to prison. See United States v. Nixon, 816 F. 2d 1022 (CA6 1987). The grand jury investigation stemmed from reports that Nixon had accepted a gratuity from a Mississippi businessman in exchange for asking a local district attorney to halt the prosecution of the businessman’s son. Because Nixon refused to resign from his office as a United States District Judge, he continued to collect his judicial salary while serving out his prison sentence. See H. R. Rep. No. 101-36, p. 13 (1989).

On May 10, 1989, the House of Representatives adopted three articles of impeachment for high crimes and misde*227meanors. The first two articles charged Nixon with giving false testimony before the grand jury and the third article charged him with bringing disrepute on the Federal Judiciary. See 135 Cong. Rec. H1811.

After the House presented the articles to the Senate, the Senate voted to invoke its own Impeachment Rule XI, under which the presiding officer appoints a committee of Senators to “receive evidence and take testimony.” Senate Impeachment Rule XI, reprinted in Senate Manual, S. Doc. No. 101-1, p. 186 (1989).1 The Senate committee held four days of hearings, during which 10 witnesses, including Nixon, testified. S. Rep. No. 101-164, p. 4 (1989). Pursuant to Rule XI, the committee presented the full Senate with a complete transcript of the proceeding and a Report stating the uncontested facts and summarizing the evidence on the contested facts. See id., at 3-4. Nixon and the House impeachment managers submitted extensive final briefs to the full Senate *228and delivered arguments from the Senate floor during the three hours set aside for oral argument in front of that body. Nixon himself gave a personal appeal, and several Senators posed questions directly to both parties. 135 Cong. Rec. S14493-14517 (Nov. 1, 1989). The Senate voted by more than the constitutionally required two-thirds majority to convict Nixon on the first two articles. Id., at S14635 (Nov. 3, 1989). The presiding officer then entered judgment removing Nixon from his office as United States District Judge.

Nixon thereafter commenced the present suit, arguing that Senate Rule XI violates the constitutional grant of authority to the Senate to “try” all impeachments because it prohibits the whole Senate from taking part in the eviden-tiary hearings. See Art. I, § 3, cl. 6. Nixon sought a declaratory judgment that his impeachment conviction was void and that his judicial salary and privileges should be reinstated. The District Court held that his claim was nonjusti-ciable, 744 F. Supp. 9 (DC 1990), and the Court of Appeals for the District of Columbia Circuit agreed. 290 U. S. App. D. C. 420, 938 F. 2d 239 (1991). We granted certiorari. 502 U. S. 1090 (1992).

A controversy is nonjusticiable — i. e., involves a political question — where there is “a textually demonstrable constitutional commitment of the issue to a coordinate political department; or a lack of judicially discoverable and manageable standards for resolving it . . . .” Baker v. Carr, 369 U. S. 186, 217 (1962). But the courts must, in the first instance, interpret the text in question and determine whether and to what extent the issue is textually committed. See ibid.; Powell v. McCormack, 395 U. S. 486, 519 (1969). As the discussion that follows makes clear, the concept of a textual commitment to a coordinate political department is not completely separate from the concept of a lack of judicially discoverable and manageable standards for resolving it; the lack of judicially manageable standards may strengthen the con-*229elusion that there is a textually demonstrable commitment to a coordinate branch.

In this case, we must examine Art. I, §3, cl. 6, to determine the scope of authority conferred upon the Senate by the Framers regarding impeachment. It provides:

“The Senate shall have the sole Power to try all Impeachments. When sitting for that Purpose, they shall be on Oath or Affirmation. When the President of the United States is tried, the Chief Justice shall preside: And no Person shall be convicted without the Concurrence of two thirds of the Members present.”

The language and structure of this Clause are revealing. The first sentence is a grant of authority to the Senate, and the word “sole” indicates that this authority is reposed in the Senate and nowhere else. The next two sentences specify requirements to which the Senate proceedings shall conform: The Senate shall be on oath or affirmation, a two-thirds vote is required to convict, and when the President is tried the Chief Justice shall preside.

Petitioner argues that the word “try” in the first sentence imposes by implication an additional requirement on the Senate in that the proceedings must be in the nature of a judicial trial. From there petitioner goes on to argue that this limitation precludes the Senate from delegating to a select committee the task of hearing the testimony of witnesses, as was done pursuant to Senate Rule XI. “ ‘[T]ry’ means more than simply Vote on’ or ‘review’ or ‘judge.’ In 1787 and today, trying a case means hearing the evidence, not scanning a cold record.” Brief for Petitioner 25. Petitioner concludes from this that courts may review whether or not the Senate “tried” him before convicting him.

There are several difficulties with this position which lead us ultimately to reject it. The word “try,” both in 1787 and later, has considerably broader meanings than those to which petitioner would limit it. Older dictionaries define try as *230“[t]o examine” or “[t]o examine as a judge.” See 2 S. Johnson, A Dictionary of the English Language (1785). In more modern usage the term has various meanings. For example, try can mean “to examine or investigate judicially,” “to conduct the trial of,” or “to put to the test by experiment, investigation, or trial.” Webster’s Third New International Dictionary 2457 (1971). Petitioner submits that “try,” as contained in T. Sheridan, Dictionary of the English Language (1796), means “to examine as a judge; to bring before a judicial tribunal.” Based on the variety of definitions, however, we cannot say that the Framers used the word “try” as an implied limitation on the method by which the Senate might proceed in trying impeachments. “As a rule the Constitution speaks in general terms, leaving Congress to deal with subsidiary matters of detail as the public interests and changing conditions may require . . . .” Dillon v. Gloss, 256 U. S. 368, 376 (1921).

The conclusion that the use of the word “try” in the first sentence of the Impeachment Trial Clause lacks sufficient precision to afford any judicially manageable standard of review of the Senate’s actions is fortified by the existence of the three very specific requirements that the Constitution does impose on the Senate when trying impeachments: The Members must be under oath, a two-thirds vote is required to convict, and the Chief Justice presides when the President is tried. These limitations are quite precise, and their nature suggests that the Framers did not intend to impose additional limitations on the form of the Senate proceedings by the use of the word “try” in the first sentence.

Petitioner devotes only two pages in his brief to negating the significance of the word “sole” in the first sentence of Clause 6. As noted above, that sentence provides that “[t]he Senate shall have the sole Power to try all Impeachments.” We think that the word “sole” is of considerable significance. Indeed, the word “sole” appears only one other time in the Constitution — with respect to the House of Representatives’ *231“sole Power of Impeachment.” Art. I, §2, cl. 5 (emphasis added). The commonsense meaning of the word “sole” is that the Senate alone shall have authority to determine whether an individual should be acquitted or convicted. The dictionary definition bears this out. “Sole” is defined as “having no companion,” “solitary,” “being the only one,” and “functioning ... independently and without assistance or interference.” Webster’s Third New International Dictionary 2168 (1971). If the courts may review the actions of the Senate in order to determine whether that body “tried” an impeached official, it is difficult to see how the Senate would be “functioning . . . independently and without .assistance or interference.”

Nixon asserts that the word “sole” has no substantive meaning. To support this contention, he argues that the word is nothing more than a mere “cosmetic edit” added by. the Committee of Style after the delegates had approved the substance of the Impeachment Trial Clause. There are two difficulties with this argument. First, accepting as we must the proposition that the Committee of Style had no authority from the Convention to alter the meaning of the Clause, see 2 Records of the Federal Convention of 1787, p. 553 (M. Far-rand ed. 1966) (hereinafter Farrand), we must presume that the Committee’s reorganization or rephrasing accurately captured what the Framers meant in their unadorned language. See Powell v. McCormack, 395 U. S., at 538-539. That is, we must presume that the Committee did its job. This presumption is buttressed by the fact that the Constitutional Convention voted on, and accepted, the Committee of Style’s linguistic version. See 2 Farrand 663-667. We agree with the Government that “the word ‘sole’ is entitled to no less weight than any other word of the text, because the Committee revision perfected what ‘had been agreed to.’ ” Brief for Respondents 25. Second, carrying Nixon’s argument to its logical conclusion would constrain us to say that the second to last draft would govern in every instance where the Com*232mittee of Style added an arguably substantive word. Such a result is at odds with the fact that the Convention passed the Committee’s version, and with the well-established rule that the plain language of the enacted text is the best indicator of intent.

Petitioner also contends that the word “sole” should not bear on the question of justiciability because Art. II, § 2, cl. 1, of the Constitution grants the President pardon authority “except in Cases of Impeachment.” He argues that such a limitation on the President’s pardon power would not have been necessary if the Framers thought that the Senate alone had authority to deal with such questions. But the granting of a pardon is in no sense an overturning of a judgment of conviction by some other tribunal; it is “[a]n executive action that mitigates or sets aside punishment for a crime.” Black’s Law Dictionary 1113 (6th ed. 1990) (emphasis added). Authority in the Senate to determine procedures for trying an impeached official, unreviewable by the courts, is therefore not at all inconsistent with authority in the President to grant a pardon to the convicted official. The exception from the President’s pardon authority of cases of impeachment was a separate determination by the Framers that executive clemency should not be available in such cases.

Petitioner finally argues that even if significance be.attributed to the word “sole” in the first sentence of the Clause, the authority granted is to the Senate, and this means that “the Senate — not the courts, not a lay jury, not a Senate Committee — shall try impeachments.” Brief for Petitioner 42. It would be possible to read the first sentence of the Clause this way, but it is not a natural reading. Petitioner’s interpretation would bring into judicial purview not merely the sort of claim made by petitioner, but other similar claims based on the conclusion that the word “Senate” has imposed by implication limitations on procedures which the Senate might adopt. Such limitations would be inconsistent with the construction of the Clause as a whole, which, as we *233have noted, sets out three express limitations in separate sentences.

The history and contemporary understanding of the impeachment provisions support our reading of the constitutional language. The parties do not offer evidence of a single word in the history of the Constitutional Convention or in contemporary commentary that even alludes to the possibility of judicial review in the context of the impeachment powers. See 290 U. S. App. D. C., at 424, 938 F. 2d, at 243; R. Berger, Impeachment: The Constitutional Problems 116 (1973). This silence is quite meaningful in light of the several explicit references to the availability of judicial review as a check on the Legislature’s power with respect to bills of attainder, ex post facto laws, and statutes. See The Federalist No. 78, p. 524 (J. Cooke ed. 1961) (“Limitations . . . can be preserved in practice no other way than through the medium of the courts of justice”).

The Framers labored over the question of where the impeachment power should lie. Significantly, in at least two considered scenarios the power was placed with the Federal Judiciary. See 1 Farrand 21-22 (Virginia Plan); id., at 244 (New Jersey Plan). Indeed, James Madison and the Committee of Detail proposed that the Supreme Court should have the power to determine impeachments. See 2 id., at 551 (Madison); id., at 178-179,186 (Committee of Detail). Despite these proposals, the Convention ultimately decided that the Senate would have “the sole Power to try all Impeachments.” Art. I, §3, cl. 6. According to Alexander Hamilton, the Senate was the “most fit depositary of this important trust” because its Members are representatives of the people. See The Federalist No. 65, p. 440 (J. Cooke ed. 1961). The Supreme Court was not the proper body because the Framers “doubted whether the members of that tribunal would, at all times, be endowed with so eminent a portion of fortitude as would be called for in the execution of so difficult a task” or whether the Court “would possess the degree of *234credit and authority” to carry out its judgment if it conflicted with the accusation brought by the Legislature — the people’s representative. See id., at 441. In addition, the Framers believed the Court was too small in number: “The awful discretion, which a court of impeachments must necessarily have, to doom to honor or to infamy the most confidential and the most distinguished characters of the community, forbids the commitment of the trust to a small number of persons.” Id., at 441-442.

There are two additional reasons why the Judiciary, and the Supreme Court in particular, were not chosen to have any role in impeachments. First, the Framers recognized that most likely there would be two sets of proceedings for individuals who commit impeachable offenses — the impeachment trial and a separate criminal trial. In fact, the Constitution explicitly provides for two separate proceedings. See Art. I, §3, cl. 7. The Framers deliberately separated the two forums to avoid raising the specter of bias and to ensure independent judgments:

“Would it be proper that the persons, who had disposed of his fame and his most valuable rights as a citizen in one trial, should in another trial, for the same offence, be also the disposers of his life and his fortune? Would there not be the greatest reason to apprehend, that error in the first sentence would be the parent of error in the second sentence? That the strong bias of one decision would be apt to overrule the influence of any new lights, which might be brought to vary the complexion of another decision?” The Federalist No. 65, p. 442 (J. Cooke ed. 1961).

Certainly judicial review of the Senate’s “trial” would introduce the same risk of bias as would participation in the trial itself.

Second, judicial review would be inconsistent with the Framers’ insistence that our system be one of checks and *235balances. In our constitutional system, impeachment was designed to be the only check on the Judicial Branch by the Legislature. On the topic of judicial accountability, Hamilton wrote:

“The precautions for their responsibility are comprised in the article respecting impeachments. They are liable to be impeached for mal-conduct by the house of representatives, and tried by the senate, and if convicted, may be dismissed from office and disqualified for holding any other. This is the only provision on the point, which is consistent with the necessary independence of the judicial character, and is the only one which we find in our own constitution in respect to our own judges.” Id., No. 79, at 532-533 (emphasis added).

Judicial involvement in impeachment proceedings, even if only for purposes of judicial review, is counterintuitive because it would eviscerate the “important constitutional check” placed on the Judiciary by the Framers. See id., No. 81, at 545. Nixon’s argument would place final reviewing authority with respect to impeachments in the hands of the same body that the impeachment process is meant to regulate.2

Nevertheless, Nixon argues that judicial review is necessary in order to place a check on the Legislature. Nixon fears that if the Senate is given unreviewable authority to interpret the Impeachment Trial Clause, there is a grave risk that the Senate will usurp judicial power. The Framers anticipated this objection and created two constitutional *236safeguards to keep the Senate in check. The first safeguard is that the whole of the impeachment power is divided between the two legislative bodies, with the House given the right to accuse and the Senate given the right to judge. Id., No. 66, at 446. This split of authority “avoids the inconvenience of making the same persons both accusers and judges; and guards against the danger of persecution from the preva-lency of a factious spirit in either of those branches.” The second safeguard is the two-thirds supermajority vote requirement. Hamilton explained that “[a]s the concurrence of two-thirds of the senate will be requisite to a condemnation, the security to innocence, from this additional circumstance, will be as complete as itself can desire.” Ibid.

In addition to the textual commitment argument, we are persuaded that the lack of finality and the difficulty of fashioning relief counsel against justiciability. See Baker v. Carr, 369 U. S., at 210. We agree with the Court of Appeals that opening the door of judicial review to the procedures used by the Senate in trying impeachments would “expose the political life of the country to months, or perhaps years, of chaos.” 290 U. S. App. D. C., at 427, 938 F. 2d, at 246. This lack of finality would manifest itself most dramatically if the President were impeached. The legitimacy of any successor, and hence his effectiveness, would be impaired severely, not merely while the judicial process was running its course, but during any retrial that a differently constituted Senate might conduct if its first judgment of conviction were invalidated. Equally uncertain is the question of what relief a court may give other than simply setting aside the judgment of conviction. Could it order the reinstatement of a convicted federal judge, or order Congress to create an additional judgeship if the seat had been filled in the interim?

Petitioner finally contends that a holding of nonjusticiability cannot be reconciled with our opinion in Powell v. McCormack, 395 U. S. 486 (1969). The relevant issue in Powell was whether courts could review the House of Representa*237tives’ conclusion that Powell was “unqualified” to sit as a Member because he had been accused of misappropriating public funds and abusing the process of the New York courts. We stated that the question of justiciability turned on whether the Constitution committed authority to the House to judge its Members’ qualifications, and if so, the extent of that commitment. Id., at 519, 521. Article I, § 5, provides that “Each House shall be the Judge of the Elections, Returns and Qualifications of its own Members.” In turn, Art. I, §2, specifies three requirements for membership in the House: The candidate must be at least 25 years of age, a citizen of the United States for no less than seven years, and an inhabitant of the State he is chosen to represent. We held that, in light of the three requirements specified in the Constitution, the word “qualifications” — of which the House was to be the Judge — was of a precise, limited nature. Id., at 522; see also The Federalist No. 60, p. 409 (J. Cooke ed. 1961) (“The qualifications of the persons who may choose or be chosen, as has been remarked upon another occasion, are defined and fixed in the constitution; and are unalterable by the legislature”) (emphasis added) (quoted in Powell, supra, at 539).

Our conclusion in Powell was based on the fixed meaning of “[qualifications” set forth in Art. I, § 2. The claim by the House that its power to “be the Judge of the Elections, Returns and Qualifications of its own Members” was a textual commitment of unreviewable authority was defeated by the existence of this separate provision specifying the only qualifications which might be imposed for House membership. The decision as to whether a Member satisfied these qualifications was placed with the House, but the decision as to what these qualifications consisted of was not.

In the case before us, there is no separate provision of the Constitution that could be defeated by allowing the Senate final authority to determine the meaning of the word “try” in the Impeachment Trial Clause. We agree with Nixon that *238courts possess power to review either legislative or executive action that transgresses identifiable textual limits. As we have made clear, “whether the action of [either the Legislative or Executive Branch] exceeds whatever authority has been committed, is itself a delicate exercise in constitutional interpretation, and is a responsibility of this Court as ultimate interpreter of the Constitution.” Baker v. Carr, supra, at 211; accord, Powell, supra, at 521. But we conclude, after exercising that delicate responsibility, that the word “try” in the Impeachment Trial Clause does not provide an identifiable textual limit on the authority which is committed to the Senate.

For the foregoing reasons, the judgment of the Court of Appeals is

Affirmed.

1

Specifically, Rule XI provides:

“[I]n the trial of any impeachment the Presiding Officer of the Senate, if the Senate so orders, shall appoint a committee of Senators to receive evidence and take testimony at such times and places as the committee may determine, and for such purpose the committee so appointed and the chairman thereof, to be elected by the committee, shall (unless otherwise ordered by the Senate) exercise all the powers and functions conferred upon the Senate and the Presiding Officer of the Senate, respectively, under the rules of procedure and practice in the Senate when sitting on impeachment trials.

“Unless otherwise ordered by the Senate, the rules of procedure and practice in the Senate when sitting on impeachment trials shall govern the procedure and practice of the committee so appointed. The committee so appointed shall report to the Senate in writing a certified copy of the transcript of the proceedings and testimony had and given before such committee, and such report shall be received by the Senate and the evidence so received and the testimony so taken shall be considered to all intents and purposes, subject to the right of the Senate to determine competency, relevancy, and materiality, as having been received and taken before the Senate, but nothing herein shall prevent the Senate from sending for any witness and hearing his testimony in open Senate, or by order of the Senate having the entire trial in open Senate.”

2

Nixon contends that justiciability should not hang on the mere fact that the Judiciary’s interest may be implicated or affected by the legislative action in question. In support, he cites our decisions in Mistretta v. United States, 488 U. S. 361 (1989), and Morrison v. Olson, 487 U. S. 654 (1988). These cases do not advance his argument, however, since neither addressed the issue of justiciability. More importantly, neither case involved a situation in which judicial review would remove the only check placed on the Judicial Branch by the Framers.

Justice Stevens,

concurring.

For me, the debate about the strength of the inferences to be drawn from the use of the words “sole” and “try” is far less significant than the central fact that the Framers decided to assign the impeachment power to the Legislative Branch. The disposition of the impeachment of Samuel Chase in 1805 demonstrated that the Senate is fully conscious of the profound importance of that assignment, and nothing in the subsequent history of the Senate’s exercise of this extraordinary power suggests otherwise. See generally 3 A. Beveridge, The Life of John Marshall 169-222 (1919); W. Rehnquist, Grand Inquests 275-278 (1992). Respect for a coordinate branch of the Government forecloses any assumption that improbable hypotheticals like those mentioned by. Justice White and Justice Souter will ever occur. Accordingly, the wise policy of judicial restraint, coupled with the potential anomalies associated with a contrary view, see ante, at 234-236, provide a sufficient justification for my agreement with the views of The Chief Justice.

*239Justice White,

with whom Justice Blackmun joins, concurring in the judgment.

Petitioner contends that the method by which the Senate convicted him on two articles of impeachment violates Art. I, § 3, cl. 6, of the Constitution, which mandates that the Senate “try” impeachments. The Court is of the view that the Constitution forbids us even to consider his contention. I find no such prohibition and would therefore reach the merits of the claim. I concur in the judgment because the Senate fulfilled its constitutional obligation to “try” petitioner.

I

It should be said at the outset that, as a practical matter, it will likely make little difference whether the Court’s or my view controls this case. This is so because the Senate has very wide discretion in specifying impeachment trial procedures and because it is extremely unlikely that the Senate would abuse its discretion and insist on a procedure that could not be deemed a trial by reasonable judges. Even taking a wholly practical approach, I would prefer not to announce an unreviewable discretion in the Senate to ignore completely the constitutional direction to “try” impeachment cases. When asked at oral argument whether that direction would be satisfied if, after a House vote to impeach, the Senate, without any procedure whatsoever, unanimously found the accused guilty of being “a bad guy,” counsel for the United States answered that the Government’s theory “leads me to answer that question yes.” Tr. of Oral Arg. 51. Especially in light of this advice from the Solicitor General, I would not issue an invitation to the Senate to find an excuse, in the name of other pressing business, to be dismissive of its critical role in the impeachment process.

Practicalities aside, however, since the meaning of a constitutional provision is at issue, my disagreement with the Court should be stated.

*240HH HH

The majority states that the question raised in this case meets two of the criteria for political questions set out in Baker v. Carr, 369 U. S. 186 (1962). It concludes first that there is “‘a textually demonstrable constitutional commitment of the issue to a coordinate political department.’ ” It also finds that the question cannot be resolved for “ ‘a lack of judicially discoverable and manageable standards.’” Ante, at 228.

Of course the issue in the political question doctrine is not whether the constitutional text commits exclusive responsibility for a particular governmental function to one of the political branches. There are numerous instances of this sort of textual commitment, e. g., Art. I, § 8, and it is not thought that disputes implicating these provisions are non-justiciable. Rather, the issue is whether the Constitution has given one of the political branches final responsibility for interpreting the scope and nature of such a power.

Although Baker directs the Court to search for “a textually demonstrable constitutional commitment” of such responsibility, there are few, if any, explicit and unequivocal instances in the Constitution of this sort of textual commitment. Conferral on Congress of the power to “Judge” qualifications of its Members by Art. I, § 5, may, for example, preclude judicial review of whether a prospective member in fact meets those qualifications. See Powell v. McCormack, 395 U. S. 486, 548 (1969). The courts therefore are usually left to infer the presence of a political question from the text and structure of the Constitution. In drawing the inference that the Constitution has committed final interpretive authority to one of the political branches, courts are sometimes aided by textual evidence that the Judiciary was not meant to exercise judicial review — a coordinate inquiry expressed in Baker’s “lack of judicially discoverable and manageable standards” criterion. See, e. g., Coleman v. Miller, 307 U. S. 433, 452-454 (1939), where the Court refused to determine *241the life span of a proposed constitutional amendment given Art. V’s placement of the amendment process with Congress and the lack of any judicial standard for resolving the question. See also id., at 457-460 (Black, J., concurring).

A

The majority finds a clear textual commitment in the Constitution’s use of the word “sole” in the phrase “[t]he Senate shall have the sole Power to try all Impeachments.” Art. I, § 3, cl. 6. It attributes “considerable significance” to the fact that this term appears in only one other passage in the Constitution. Ante, at 230. See Art. I, § 2, cl. 5 (the House of Representatives “shall have the sole Power of Impeachment”). The Framers’ sparing use of “sole” is thought to indicate that its employment in the Impeachment Trial Clause demonstrates a concern to give the Senate exclusive interpretive authority over the Clause.

In disagreeing with the Court, I note that the Solicitor General stated at oral argument that “[w]e don’t rest our submission on sole power to try.” Tr. of Oral Arg. 32; see also id., at 51. The Government was well advised in this respect. The significance of the Constitution’s use of the term “sole” lies not in the infrequency with which the term appears, but in the fact that it appears exactly twice, in parallel provisions concerning impeachment. That the word “sole” is found only in the House and Senate Impeachment Clauses demonstrates that its purpose is to emphasize the distinct role of each in the impeachment process. As the majority notes, the Framers, following English practice, were very much concerned to separate the prosecutorial from the adjudicative aspects of impeachment. Ante, at 235-236 (citing The Federalist No. 66, p. 446 (J. Cooke ed. 1961)). Giving each House “sole” power with respect to its role in impeachments effected this division of labor. While the majority is thus right to interpret the term “sole” to indicate that the Senate ought to “ Tunctio[n] independently *242and without assistance or interference,’” ante, at 231, it wrongly identifies the Judiciary, rather than the House, as the source of potential interference with which the Framers were concerned when they employed the term “sole.”

Even if the Impeachment Trial Clause is read without regard to its companion Clause, the Court’s willingness to abandon its obligation to review the constitutionality of legislative acts merely on the strength of the word “sole” is perplexing. Consider, by comparison, the treatment of Art. I, § 1, which grants “All legislative powers” to the House and Senate. As used in that context “all” is nearly synonymous with “sole” — both connote entire and exclusive authority. Yet the Court has never thought it would unduly interfere with the operation of the Legislative Branch to entertain difficult and important questions as to the extent of the legislative power. Quite the opposite, we have stated that the proper interpretation of the Clause falls within the province of the Judiciary. Addressing the constitutionality of the legislative veto, for example, the Court found it necessary and proper to interpret Art. I, § 1, as one of the “[e]xplicit and unambiguous provisions of the Constitution [that] prescribe and define the respective functions of the Congress and of the Executive in the legislative process.” INS v. Chadha, 462 U. S. 919, 945 (1983).

The majority also claims support in the history and early interpretations of the Impeachment Clauses, noting the various arguments in support of the current system made at the Constitutional Convention and expressed powerfully by Hamilton in The Federalist Nos. 65 and 66. In light of these materials there can be little doubt that the Framers came to the view at' the Convention that the trial of officials’ public misdeeds should be conducted by representatives of the people; that the fledgling Judiciary lacked the wherewithal to adjudicate political intrigues; that the Judiciary ought not to try both impeachments and subsequent criminal cases emanating from them; and that the impeachment power must *243reside in the Legislative Branch to provide a check on the largely unaccountable Judiciary.

The majority’s review of the historical record thus explains why the power to try impeachments properly resides with the Senate. It does not explain, however, the sweeping statement that the Judiciary was “not chosen to have any role in impeachments.”1 Ante, at 234. Not a single word in the historical materials cited by the majority addresses judicial review of the Impeachment Trial Clause. And a glance at the arguments surrounding the Impeachment Clauses negates the majority’s attempt to infer nonjusticia-bility from the Framers’ arguments in support of the Senate’s power to try impeachments.

What the relevant history mainly reveals is deep ambivalence among many of the Framers over the very institution of impeachment, which, by its nature, is not easily reconciled with our system of checks and balances. As they clearly recognized, the branch of the Federal Government which is possessed of the authority to try impeachments, by having final say over the membership of each branch, holds a potentially unanswerable power over the others. In addition, that branch, insofar as it is called upon to try not only members of other branches, but also its own, will have the advantage of being the judge of its own members’ causes.

It is no surprise, then, that the question of impeachment greatly vexed the Framers. The pages of the Convention debates reveal diverse plans for resolving this exceedingly difficult issue. See P. Hoffer & N. Hull, Impeachment in America, 1635-1805, pp. 97-106 (1984) (discussing various proposals). Both before and during the Convention, Madison maintained that the Judiciary ought to try impeachments. Id., at 74, 98,100. Shortly thereafter, however, he devised a quite complicated scheme that involved the partici*244pation of each branch. Id., at 74-75. Jefferson likewise had attempted to develop an interbranch system for impeachment trials in Virginia. Id., at 71-72. Even Hamilton’s eloquent defense of the scheme adopted by the Constitution was based on a pragmatic decision to further the cause of ratification rather than a strong belief in the superiority of a scheme vesting the Senate with the sole power to try impeachments. While at the Convention, Hamilton advocated that impeachment trials be conducted by a court made up of state-court judges. 1 Records of the Federal Convention of 1787, pp. 292-293 (M. Farrand ed. 1966). Four months after publishing The Federalist Nos. 65 and 66, however, he urged the New York Ratifying Convention to amend the Clause he had so ably defended to have the Senate, the Supreme Court, and judges from each State jointly try impeachments. 5 The Papers of Alexander Hamilton 167-168 (H. Syrett ed. 1962).

The historical evidence reveals above all else that the Framers were deeply concerned about placing in any branch the “awful discretion, which a court of impeachments must necessarily have.” The Federalist No. 65, p. 441 (J. Cooke ed. 1961). Viewed against this history, the discord between the majority’s position and the basic principles of checks and balances underlying the Constitution’s separation of powers is clear. In essence, the majority suggests that the Framers’ conferred upon Congress a potential tool of legislative dominance yet at the same time rendered Congress’ exercise of that power one of the very few areas of legislative authority immune from any judicial review. While the majority rejects petitioner’s justiciability argument as espousing a view “inconsistent with the Framers’ insistence that our system be one of checks and balances,” ante, at 234, it is the Court’s finding of nonjusticiability that truly upsets the Framers’ careful design. In a truly balanced system, impeachments tried by the Senate would serve as a means of *245controlling the largely unaccountable Judiciary, even as judicial review would ensure that the Senate adhered to a minimal set of procedural standards in conducting impeachment trials.

B

The majority also contends that the term “try” does not present a judicially manageable standard. It notes that in 1787, as today, the word “try” may refer to an inquiry in the nature of a judicial proceeding, or, more generally, to experimentation or investigation. In light of the term’s multiple senses, the Court finds itself unable to conclude that the Framers used the word “try” as “an implied limitation on the method by which the Senate might proceed in trying impeachments.” Ante, at 280. Also according to the majority, comparison to the other more specific requirements listed in the Impeachment Trial Clause — that the senators must proceed under oath and vote by two-thirds to convict, and that the Chief Justice must preside over an impeachment trial of the President — indicates that the word “try” was not meant by the Framers to constitute a limitation on the Senate’s conduct and further reveals the term’s unmanageability.

It is apparently on this basis that the majority distinguishes Powell v. McCormack, 395 U. S. 486 (1969). In Powell, the House of Representatives argued that the grant to Congress of the power to “Judge” the qualifications of its members in Art. I, § 5, precluded the Court from reviewing the House’s decision that Powell was not fit for membership. We held to the contrary, noting that, although the Constitution leaves the power to “Judge” in the hands of Congress, it also enumerates, in Art. I, §2, the “qualifications” whose presence or absence Congress must adjudge. It is precisely the business of the courts, we concluded, to determine the nature and extent of these constitutionally specified qualifications. Id., at 522. The majority finds this case different from Powell only on the grounds that, whereas the qualifi*246cations of Art. I, § 2, are readily susceptible to judicial interpretation, the term “try” does not provide an “identifiable textual limit on the authority which is committed to the Senate.” Ante, at 238.

This argument comes in two variants. The first, which asserts that one simply cannot ascertain the sense of “try” which the Framers employed and hence cannot undertake judicial review, is clearly untenable. To begin with, one would intuitively expect that, in defining the power of a political body to conduct an inquiry into official wrongdoing, the Framers used “try” in its legal sense. That intuition is borne out by reflection on the alternatives. The third Clause of Art. I, § 3, cannot seriously be read to mean that the Senate shall “attempt” or “experiment with” impeachments. It is equally implausible to say that the Senate is charged with “investigating” impeachments given that this description would substantially overlap with the House of Representatives’ “sole” power to draw up articles of impeachment. Art. I, §2, cl. 5. That these alternatives are not realistic possibilities is finally evidenced by the use of “tried” in the third sentence of the Impeachment Trial Clause (“[w]hen the President of the United States is tried . . .”), and by Art. Ill, §2, cl. 3 (“[t]he Trial of all Crimes, except in Cases of Impeachment. . .”).

The other variant of the majority position focuses not on which sense of “try” is employed in the Impeachment Trial Clause, but on whether the legal sense of that term creates a judicially manageable standard. The majority concludes that the term providés no “identifiable textual limit.” Yet, as the Government itself conceded at oral argument, the term “try” is hardly so elusive as the majority would have it. See Tr. of Oral Arg. 51-52. Were the Senate, for example, to adopt the practice of automatically entering a judgment of conviction whenever articles of impeachment were delivered from the House, it is quite clear that the Senate *247will have failed to “try” impeachments.2 See id., at 52. Indeed in this respect, “try” presents no greater, and perhaps fewer, interpretive difficulties than some other constitutional standards that have been found amenable to familiar techniques of judicial construction, including, for example, “Commerce . . . among the several States,” Art. I, §8, cl. 3, and “due process of law,” Arndt. 5. See Gibbons v. Ogden, 9 Wheat. 1, 189 (1824) (“The subject to be regulated is commerce; and our constitution being . . . one of enumeration, and not of definition, to ascertain the extent of the power, it becomes necessary to settle the meaning of the word”); Mathews v. Eldridge, 424 U. S. 319, 334 (1976) (“‘“[D]ue process,” unlike some legal rules, is not a technical conception with a fixed content unrelated to time, place and circumstances’”) (quoting Cafeteria & Restaurant Workers v. McElroy, 367 U. S. 886, 895 (1961)).3

*248III

The majority’s conclusion that “try” is incapable of judicial construction is not without irony. One might think that if any class of concepts would fall within the definitional abilities of the Judiciary, it would be that class having to do with procedural justice. Examination of the remaining question-whether proceedings in accordance with Senate Rule XI are compatible with the Impeachment Trial Clause-confirms this intuition.

Petitioner bears the rather substantial burden of demonstrating that, simply by employing the word “try,” the Constitution prohibits the Senate from relying on a factfinding committee. It is clear that the Framers were familiar with English impeachment practice and with that of the States employing a variant of the English model at the time of the Constitutional Convention. Hence there is little doubt that the term “try” as used in Art. I, §3, cl. 6, meant that the Senate should conduct its proceedings in a manner somewhat resembling a judicial proceeding. Indeed, it is safe to assume that Senate trials were to follow the practice in England and the States, which contemplated a formal hearing on the charges, at which the accused would be represented by counsel, evidence would be presented, and the accused would have the opportunity to be heard.

Petitioner argues, however, that because committees were not used in state impeachment trials prior to the Convention, the word “try” cannot be interpreted to permit their use. It is, however, a substantial leap to infer from the absence of a particular device of parliamentary procedure that its use has been forever barred by the Constitution. And there is textual and historical evidence that undermines the inference sought to be drawn in this case.

The fact that Art. Ill, §2, cl. 3, specifically exempts impeachment trials from the jury requirement provides some evidence that the Framers were anxious not to have additional specific procedural requirements read into the term *249“try.” Contemporaneous commentary further supports this view. Hamilton, for example, stressed that a trial by so large a body as the Senate (which at the time promised to boast 26 members) necessitated that the proceedings not “be tied down to . . . strict rules, either in the delineation of the offence by the prosecutors, or in the construction of it by the Judges . . . .” The Federalist No. 65, p. 441 (J. Cooke ed. 1961). In his extensive analysis of the Impeachment Trial Clause, Justice Story offered a nearly identical analysis, which is worth quoting at length.

“[I]t is obvious, that the strictness of the forms of proceeding in cases of offences at common law is ill adapted to impeachments. The very habits growing out of judicial employments; the rigid manner, in which the discretion of judges is limited, and fenced in on all sides, in order to protect persons accused of crimes by rules and precedents; and the adherence to technical principles, which, perhaps, distinguishes this branch of the law, more than any other, are all ill adapted to the trial of political offences, in the broad course of impeachments. And it has been observed with great propriety, that a tribunal of a liberal and comprehensive character, confined, as little as possible, to strict forms, enabled to continue its session as long as the nature of the law may require, qualified to view the charge in all its bearings and dependencies, and to appropriate on sound principles of public policy the defence of the accused, seems indispensable to the value of the trial. The history of impeachments, both in England and America, justifies the remark. There is little technical in the mode of proceeding; the charges are sufficiently clear, and yet in a general form; there are few exceptions, which arise in the application of the evidence, which grow out of mere technical rules and quibbles. And it has repeatedly been seen, that the functions have been better understood, and more liberally and justly expounded by states*250men, then by mere lawyers.” 1 J. Story, Commentaries on the Constitution of the United States §765, p. 532 (3d ed. 1858).

It is also noteworthy that the delegation of factfinding by judicial and quasi-judicial bodies was hardly unknown to the Framers. Jefferson, at least, was aware that the House of Lords sometimes delegated factfinding in impeachment trials to committees and recommended use of the same to the Senate. T. Jefferson, A Manual of Parliamentary Practice for the Use of the Senate of the United States § LIII (2d ed. 1812) (“The practice is to swear the witnesses in open House, and then examine them there: or a committee may be named, who shall examine them in committee . . .”), reprinted in Jefferson’s Parliamentary Writings, The Papers of Thomas Jefferson, Second Series 424 (W. Howell ed. 1988). The States also had on occasion employed legislative committees to investigate whether to draw up articles of impeachment. See Hoffer & Hull, Impeachment in America, at 29, 33. More generally, in colonial governments and state legislatures, contemnors appeared before committees to answer the charges against them. See Groppi v. Leslie, 404 U. S. 496, 501 (1972). Federal courts likewise had appointed special masters and other factfinders “[f]rom the commencement of our Government.” Ex parte Peterson, 253 U. S. 300, 312 (1920). Particularly in light of the Constitution’s grant to each House of the power to “determine the Rules of its Proceedings,” see Art. I, § 5, cl. 2, the existence of legislative and judicial delegation strongly suggests that the Impeachment Trial Clause was not designed to prevent employment of a factfinding committee.

In short, textual and historical evidence reveals that the Impeachment Trial Clause was not meant to bind the hands of the Senate beyond establishing a set of minimal procedures. Without identifying the exact contours of these procedures, it is sufficient to say that the Senate’s use of a fact-finding committee under Rule XI is entirely compatible with *251the Constitution’s command that the Senate “try all impeachments.” Petitioner’s challenge to his conviction must therefore fail.

IV

Petitioner has not asked the Court to conduct his impeachment trial; he has asked instead that it determine whether his impeachment was tried by the Senate. The majority refuses to reach this determination out of a laudable desire to respect the authority of the Legislature. Regrettably, this concern is manifested in a manner that does needless violence to the Constitution.4 The deference that is owed can *252be found in the Constitution itself, which provides the Senate ample discretion to determine how best to try impeachments.

Justice Souter,

concurring in the judgment.

I agree with the Court that this case presents a nonjusti-ciable political question. Because my analysis differs somewhat from the Court’s, however, I concur in its judgment by this separate opinion.

As we cautioned in Baker v. Carr, 369 U. S. 186, 210-211 (1962), “the ‘political question’ label” tends “to obscure the need for case-by-case inquiry.” The need for such close examination is nevertheless clear from our precedents, which demonstrate that the functional nature of the political question doctrine requires analysis of “the precise facts and posture of the particular case,” and precludes “resolution by any semantic cataloguing,” id., at 217:

“Prominent on the surface of any case held to involve a political question is found a textually demonstrable constitutional commitment of the issue to a coordinate political department; or a lack of judicially discoverable and manageable standards for resolving it; or the impossibility of deciding without an initial policy determination of a kind clearly for nonjudicial discretion; or the impossibility of a court’s undertaking independent resolution without expressing lack of the respect due coordinate branches of government; or an unusual need for unquestioning adherence to a political decision already made; or the potentiality 'of embarrassment from multifarious pronouncements by various departments on one question.” Ibid.

Whatever considerations feature most prominently in a particular case, the political question doctrine is “essentially a function of the separation of powers,” ibid., existing to restrain courts “from inappropriate interference in the business of the other branches of Government,” United States v. *253Munoz-Flores, 495 U. S. 385, 394 (1990), and deriving in large part from prudential concerns about the respect we owe the political departments, see Goldwater v. Carter, 444 U. S. 996, 1000 (1979) (Powell, J., concurring in judgment); A. Bickel, The Least Dangerous Branch 125-126 (2d ed. 1986); Finkelstein, Judicial Self-Limitation, 37 Harv. L. Rev. 338, 344-345 (1924). Not all interference is inappropriate or disrespectful, however, and application of the doctrine ultimately turns, as Learned Hand put it, on “how importunately the occasion demands an answer.” L. Hand, The Bill of Rights 15 (1958).

This occasion does not demand an answer. The Impeachment Trial Clause commits to the Senate “the sole Power to try all Impeachments,” subject to three procedural requirements: the Senate shall be on oath or affirmation; the Chief Justice shall preside when the President is tried; and conviction shall be upon the concurrence of two-thirds of the Members present. U. S. Const., Art. I, § 3, cl. 6. It seems fair to conclude that the Clause contemplates, that the Senate may determine, within broad boundaries, such subsidiary issues as the procedures for receipt and consideration of evidence necessary to satisfy its duty to “try” impeachments. Other significant considerations confirm a conclusion that this case presents a nonjusticiable political question: the “unusual need for unquestioning adherence to a political decision already made,” as well as “the potentiality of embarrassment from multifarious pronouncements by various departments on one question.” Baker, supra, at 217. As the Court observes, see ante, at 236, judicial review of an impeachment trial would under the best of circumstances entail significant disruption of government.

One can, nevertheless, envision different and unusual circumstances that might justify a more searching review of impeachment proceedings. If the Senate were to act in a manner seriously threatening the integrity of its results, convicting, say, upon a coin toss, or upon a summary determination that an officer of the United States was simply “ ‘a bad *254guy/ ” ante, at 239 (White, J., concurring in judgment), judicial interference might well be appropriate. In such circumstances, the Senate’s action might be so far beyond the scope of its constitutional authority, and the consequent impact on the Republic so great, as to merit a judicial response despite the prudential concerns that would ordinarily counsel silence. “The political question doctrine, a tool for maintenance of governmental order, will not be so applied as to promote only disorder.” Baker, supra, at 215.

1

This latter contention is belied by the Impeachment Trial Clause itself, which designates the Chief Justice to preside over impeachment trials of the President.

2

It is not a sufficient rejoinder to this example to say, with one of the Court of Appeals judges below, that it postulates a “monstrous hypothetical abuse.” See 290 U. S. App. D. C. 420, 427, 938 F. 2d 239, 246 (1991). The unlikelihood of the example being realized does not undermine the point that “try” has a definable meaning and thus ought to be regarded as judicially manageable.

3

The majority’s in terrorem argument against justiciability — that judicial review of impeachments might cause national disruption and that the courts would be unable to fashion effective relief — merits only brief attention. In the typical instance, court review of impeachments would no more render the political system dysfunctional than has this litigation. Moreover, the same capacity for disruption was noted and rejected as a basis for not hearing Powell. Powell v. McCormack, 395 U. S. 486, 549 (1969). The relief granted for unconstitutional impeachment trials would presumably be similar to the relief granted to other unfairly tried public employee-litigants. Finally, as applied to the special ease of the President, the majority’s argument merely points out that, were the Senate to convict the President without any kind of a trial, a constitutional crisis might well result. It hardly follows that the Court ought to refrain from upholding the Constitution in all impeachment cases. Nor does it follow that, in cases of Presidential impeachment, the Justices ought to abandon their constitutional responsibilities because the Senate has precipitated a crisis.

4

Although our views might well produce identical results in most cases, the same objection may be raised against the prudential version of political question doctrine presented by Justice Souter. According to the prudential view, judicial determination of whether the Senate has conducted an impeachment trial would interfere unacceptably with the Senate’s work and should be avoided except where necessitated by the threat of grave harm to the constitutional order. As articulated, this position is missing its premise: No explanation is offered as to why it would show disrespect or cause disruption or embarrassment to review the action of the Senate in this case as opposed to, say, the enactment of legislation under the Commerce Clause. The Constitution requires the courts to determine the validity of statutes passed by Congress when they are challenged, even though such laws are passed with the firm belief that they are constitutional. The exercise of judicial review of this kind, with all of its attendant risk of interference and disrespect, is not conditioned upon a showing in each case that without it the Republic would be at risk. Some account is therefore needed as to why prudence does not counsel against judicial review in the typical case, yet does so in this case.

In any event, the prudential view cannot achieve its stated purpose. The judgment it wishes to avoid — and the attendant disrespect and embarrassment — will inevitably be cast because the courts still will be required to distinguish cases on their merits. Justice Souter states that the Court ought not to entertain petitioner’s constitutional claim because “[i]t seems fair to conclude,” post, at 263, that the Senate tried him. In other words, on the basis of a preliminary determination that the Senate has acted within the “broad boundaries” of the Impeachment Trial Clause, it is concluded that we must refrain from making that determination. At best, this approach offers only the illusion of deference and respect by substituting impressionistic assessment for constitutional analysis.