Constitutional Law--Legislative Immunity Outweighs First Amendment Rights

In Eastland v. United States Servicemen\u27s Fund the United States Supreme Court held that even in the face of an alleged infringement of first amendment rights, when a Senate subcommittee\u27s activity falls within the legitimate legislative sphere, the speech or debate clause of the United States Constitution protects the activities of the subcommittee, the individual senators and the chief counsel, thereby prohibiting judicial interference to enjoin a subpoena issued by the subcommittee