Although the original proposal to give each house of Congress the power to expel lacked a supermajority requirement, James Madison, pointing out the danger that a majority faction could abuse its power by expelling Members of the minority, successfully moved to insert the two-thirds rule. Unlike the exclusion power of Article I, Section 5, Clause 1, there are no judicially enforceable constitutional standards limiting the use of the expulsion power other than the supermajority requirement. In re Chapman (1897). Moreover, the courts generally regard disputes arising from the procedural rules of Congress as nonjusticiable (not amenable to judicial review), unless Congress “ignores constitutional restraints or violates fundamental rights.” United States v. Ballin (1892). Powell v. McCormack (1969), for example, assumed that the case would be nonjusticiable if two-thirds of the House had “expelled” Congressman Adam Clayton Powell instead of “excluding” him.

The Expulsion Clause stands as the analog to the impeachment clauses. It is the only constitutional mechanism by which a sitting Member of Congress can be removed from office. Alexander Hamilton assumed that Members of the legislature could be impeached, and some comments in the ratifying conventions presumed the same. Some scholarly commentary suggest that the various ways in which the Constitution refers to the term “officer” may indicate that Members of the legislature could be impeached, but historical practice has been to the contrary. In 1797, the Senate expelled William Blount, but it later refused to convict him on a bill of impeachment because it concluded that there was a lack of jurisdiction. Subsequent interpretation of the Senate’s action, supported in particular by Justice Joseph Story, has found the Senate’s action dispositive: Members of Congress may be expelled by their own respective body, but they cannot be impeached. Story’s position is supported at least in part by the text of the Constitution. The existence of the specific removal provisions for Members of Congress negates any inference that impeachment exists as an alternative removal mechanism.

Since 1789, the Senate has had nine expulsion proceedings out of which fifteen Senators were expelled, most of them early in the Civil War on grounds of supporting the rebellion. The House has also proceeded against twenty-nine of its Members but has expelled only five, two for corruption and three for supporting the rebellion.

More frequent have been instances when each house has punished its respective Members by a simple majority. Punishments have included censure (or the somewhat lesser “denouncement”), reprimand, loss of seniority, removal from committee or subcommittee chairmanship, and fine. Each house sets its own procedures for punishments less than expulsion. Conviction is by a simple majority. There have been a total of nine Senators and twenty-three House members censured. Censure in the House is more formal. The censured Member must rise while the Speaker reads aloud the actions for which he is being rebuked. In addition, when a Member of Congress is convicted of a crime, he is expected to refrain from voting unless and until his conviction is overturned or he is reelected.

One important recent development is the establishment of the Office of Congressional Ethics, an internal entity charged with reviewing allegations of misconduct and recommending action to the House Ethics Committee. The Senate has not taken similar action.