Senate Expulsion, Censure, and Discipline of Members

The United States Senate holds constitutional authority to police its own membership through three distinct disciplinary mechanisms: expulsion, censure, and lesser sanctions administered through its ethics process. These powers derive directly from Article I, Section 5 of the Constitution and represent one of the few areas where the Senate operates as a self-governing body insulated from judicial review. Understanding how each mechanism works, when each applies, and what thresholds must be met is essential to understanding the Senate as an institution of constitutional self-regulation, a subject explored more broadly across senateauthority.com.

Definition and Scope

Senate discipline encompasses the formal tools the chamber may employ against its own members for misconduct, whether criminal, ethical, or related to the conduct of official duties. The constitutional basis is compact but broad: Article I, Section 5, Clause 2 states that "each House may… punish its Members for disorderly Behaviour, and, with the Concurrence of two thirds, expel a Member."

Three recognized categories of discipline exist:

1. Expulsion — Permanent removal from the Senate, requiring a two-thirds supermajority vote of members present.
2. Censure — A formal public condemnation passed by simple majority vote; the member retains the seat.
3. Lesser sanctions — Reprimands, fines, loss of committee assignments, or other penalties administered through the Senate Select Committee on Ethics.

Censure and expulsion are distinct in both threshold and consequence. Expulsion ends a senator's tenure entirely; censure is declaratory, placing a formal rebuke in the Senate record without altering the member's status, voting rights, or seniority. The Senate has also on occasion used a resolution of "denouncement," which functions similarly to censure but is considered a somewhat weaker formulation.

How It Works

Expulsion

An expulsion proceeding begins when one or more senators introduce a resolution calling for the removal of a colleague. The resolution is typically referred to the Senate Select Committee on Ethics for investigation and a recommendation, though the full Senate is not obligated to wait for a committee report before voting. The chamber then votes, and removal requires two-thirds of senators present and voting — not two-thirds of all 100 members — a distinction that matters when seats are vacant or members are absent.

The Senate has expelled 15 members in its history, 14 of whom were removed in 1861 and 1862 for supporting the Confederacy (United States Senate Historical Office). The only expulsion outside that period was William Blount of Tennessee in 1797, for conspiring with British agents.

Censure

A censure resolution proceeds by simple majority and does not require committee referral, though the Ethics Committee frequently investigates underlying conduct before the full Senate acts. Upon adoption, the censured senator is typically required to stand in the well of the chamber while the presiding officer reads the resolution aloud — a formal, public humiliation without legal consequence. The Senate has censured 9 members since its founding (Senate Historical Office), the most prominent being the censure of Senator Joseph McCarthy in 1954, which used the term "condemned" rather than censured.

Ethics Committee Process

The Senate Select Committee on Ethics, a six-member bipartisan panel established in 1964, handles formal complaints against senators. Its process includes four phases:

1. Complaint receipt or preliminary inquiry — The committee evaluates whether allegations meet the threshold for investigation.
2. Preliminary investigation — Staff investigators gather evidence; no public announcement is required at this stage.
3. Adjudicatory hearing — If the preliminary investigation finds substantial credibility, a formal adjudicatory hearing is held with the senator's right to respond.
4. Recommended disposition — The committee may recommend dismissal, public or private letters of admonition, reprimand, censure, expulsion, or referral to law enforcement.

Common Scenarios

Senate discipline has historically clustered around recognizable fact patterns:

• Disloyalty or sedition — The 1861–1862 expulsions for Confederate allegiance remain the dominant precedent.
• Financial misconduct — Senator Harrison Williams was convicted under the ABSCAM investigation in 1981 and resigned before a scheduled expulsion vote; Senator Bob Packwood resigned in 1995 after the Ethics Committee recommended expulsion following findings of sexual misconduct and abuse of official power.
• Campaign finance violations — The Keating Five investigation (1989–1992) examined five senators for improper intervention with federal banking regulators on behalf of Charles Keating's Lincoln Savings and Loan; the committee issued reprimands of varying severity to 4 of the 5 senators.
• Physical assault — The 1856 caning of Senator Charles Sumner by a House member fell outside the Senate's disciplinary jurisdiction, but Sumner's empty seat became a symbol driving debate about what internal discipline could and could not address.

Decision Boundaries

The Senate's disciplinary authority is bounded by several structural constraints that determine when each tool is appropriate and when it may not apply.

Jurisdiction: The Ethics Committee's authority extends to conduct that reflects upon the Senate as an institution, whether the act occurred in an official or personal capacity. Not all criminal convictions automatically trigger expulsion proceedings — the Senate evaluates whether the conduct is incompatible with continued service.

Pre-service conduct: The Senate has generally declined to punish members for conduct occurring before they took office. The Ethics Committee issued guidance in the cases of Senators David Durenberger (1990) and others that pre-Senate conduct lies outside the committee's primary jurisdiction.

Expulsion vs. censure thresholds: Expulsion demands the two-thirds supermajority precisely because the framers regarded removal from elected office as the most extreme sanction. Censure requires only a simple majority but carries no legal force. This asymmetry means the Senate may censure when it cannot muster the votes to expel — a political reality evident in the McCarthy censure, where the two-thirds bar for expulsion was never seriously pursued.

Interaction with criminal process: Senate discipline and criminal prosecution are parallel, not sequential. The Department of Justice may prosecute a senator independently of any Ethics Committee action, and a criminal conviction does not automatically trigger expulsion. The Senate retains full discretion. Senators facing prosecution have historically resigned before expulsion votes, as occurred in the cases of Williams and Packwood.

Judicial review: Federal courts have consistently declined to intervene in Senate disciplinary proceedings on separation-of-powers grounds, treating such actions as a "political question" committed to the legislature by the Constitution's text. This boundary insulates the Senate's disciplinary function from external override.

For additional context on the constitutional foundation that grants these self-regulatory powers, the senate-constitutional-basis page addresses Article I authorities in full.