Protection from legal actions given to members of Congress by the speech and debate clause of Article I, section 6, of the U.S. Constitution.
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
Congress, qualifications for
Executive immunity
Federalism
Kilbourn v. Thompson
Separation of powers
Speech and debate clause