A legal doctrine that protects legislators from being sued for all actions taken in the sphere of legitimate legislative activity. The purpose of legislative immunity is to ensure that the legislative function may be performed independently without fear of outside interference.
Legislative immunity is granted to Congress by the Speech or Debate Clause in Article I of the Constitution and has been extended to state and local legislators through the federal common law. Additionally, 43 states have speech or debate clauses in their own constitutions. Legislative immunity also extends to officials outside the legislative branch participating in the legislative process. For example, a mayor presenting a budget to the city council. However, acts that are unrelated to a legislator’s duties (e.g. defamatory statements made during a press conference) and acts that occur without lawful authority (e.g. unconstitutional procedures for enacting legislation or a subcommittee investigator illegally seizing documents without a subpoena) are not immune.
[Last updated in June of 2020 by the Wex Definitions Team]