[2] Censure, a less severe form of disciplinary action, is an official sanction of a member.
Presently, the disciplinary process begins when a resolution to expel or censure a member is referred to the appropriate committee.
In the entire history of the United States Congress, 21 members have been expelled: 15 from the Senate and six from the House of Representatives.
Censure has been a much more common form of disciplinary action in Congress over the years, as it requires a much lower threshold of votes to impose.
In many of those instances members under serious threat of expulsion resigned, including: There were other instances in which investigations were brought, but the defendants were exonerated, expulsion was rejected, insufficient evidence was found, or the member's term expired: