legislative immunity

It is the purpose and office of the doctrine of legislative immunity, having its roots as it does in the Speech or Debate Clause of the Constitution, that legislators engaged 'in the sphere of legitimate legislative activity' should be protected not only from the consequences of litigation's results but also from the burden of defending themselves. This Court has held, however, that this doctrine is less absolute, although applicable, when applied to officers or employees of a legislative body, rather than to legislators themselves.

Defined by the Supreme Court in - Dombrowski v. Eastland, 387 U.S. 82 (1967).