Congress, arrest and immunity of members of
Significance: The primary purpose of the speech and debate clause is to preserve the notion of separation of powers by protecting the legislative branch from interference by the executive and judicial branches.
The speech and debate clause was originally intended to protect Congress and its members from attempts by other branches of government to interfere with and disrupt Congress's ability to do its work. Although the clause appears to offer absolute immunity, the Supreme Court has narrowed its scope through a series of rulings. In Kilbourn v. Thompson (1881), the Court provided a broad interpretation of the clause and held that its protection extended to activity generally engaged in during a House session by its members in relation to the business before the House. Subsequent Court decisions determined that the clause may be asserted in both civil and criminal actions. However, the clause protects only legislative activities, not political matters. In Gravel v. United States (1972), the Court held that only those acts that are integral parts of the legislative process receive protection. Protected legislative activities include voting, speaking, debating, preparing committee reports, and conducting committee hearings. Unprotected political activities include publishing books, distributing press releases, creating constituent newsletters, delivering speeches outside Congress, and providing constituent services. In Gravel, the Court further held that the clause's protection extends to a member's aide, as long as the services the aide performs would be immune legislative conduct if performed by a member.