Article 1, Section 5, Clauses 1--4
William Rawle, A View of the Constitution of the United States 46--48 1829 (2d ed.)
Both the senate and house of representatives possess the usual powers to judge of the elections, returns and qualifications of their own members, and to punish them for disorderly behaviour, which may be carried to the extent of expulsion, provided two-thirds concur.
It has not yet been precisely settled what must be the disorderly behavour to incur punishment, nor what kind of punishment is to be inflicted; but it cannot be doubted that misbehaviour out of the walls of the house or within them, when it is not in session, would not fall within the meaning of the Constitution.
Expulsion may, however, be founded on criminal conduct committed in any place, and either before or after conviction in a court of law.
But a power extending beyond their own precincts, and affecting others than their own members, has been exercised by both houses, and has been decided in the supreme court to be constitutional.
It is a maxim in the practical application of government, that the public functionaries should be supported in the full exercise of the powers intrusted to them. Attempts to bribe or to intimidate them constitute offences against the public. They amount to more than contempts or breaches of privilege against the legislative bodies, and they undoubtedly subject the offenders to the usual course of prosecution and punishment in the courts of law. But this liability does not exclude the immediate jurisdiction of the legislative body, which is supported by strong considerations of public policy. The people are entitled to the utmost purity and integrity in the conduct of their representatives. The house is a guardian of the public interests in this respect. It is its duty to make immediate inquiry as to any attempt to assail the freedom or corrupt the integrity of any of its members. From the duty to inquire arises the right to punish; it needs not to be devolved on the ordinary tribunals. It is true that no power to this effect is expressly given by the Constitution, nor does the judicial or criminal power given to the courts of the United States in any part, expressly extend to the infliction of punishment for such offences. But it is not therefore to be inferred that no such power exists any where. If the courts of the United States would possess it by implication, there is no reason for refusing it to the legislative body itself, unless it should be discovered to be wholly inconsistent with the construction or nature of that body, or with some clause in the Constitution. But the reverse of the first position is the truth. It would be inconsistent with the nature of such a body to deny it the power of protecting itself from injury or insult. If its deliberations are not perfectly free, its constituents are eventually injured. This power has never been denied in any country, and is incidental to the nature of all legislative bodies. If it possesses such a power in the case of an immediate insult, or disturbance preventing the exercise of its ordinary functions, it is impossible to deny it in other cases, which although less immediate or less violent, partake of the same character, by having a tendency to impair the firm and honest discharge of public duties.
Those clauses in the Constitution which provide that the trial of all crimes shall be by jury, in the state and district where the offence has been committed, are ever to be held sacred--but it would be doing violence to them to carry them further than the plain meaning, that trial by jury shall be preserved in criminal prosecutions in the ordinary courts; otherwise it would be impossible to support the jurisdiction given to the senate in cases of impeachment, wherein no trial by jury takes place. It appears then that this implied power of punishing what are termed contempts and infringements of the privileges of the houses, is in reality the useful institution of a summary jurisdiction for the punishment of offences substantially committed against the people, and that it is correctly deduced from the Constitution.
The Founders' Constitution
Volume 2, Article 1, Section 5, Clauses 1--4, Document 20
The University of Chicago Press
Rawle, William. A View of the Constitution of the United States of America. 2d ed. Philadelphia, 1829. Reprint. New York: Da Capo Press, 1970.
Easy to print version.