The agents of the Federal Bureau of Investigation violated the Constitution when they viewed legislative papers in Mr. Jefferson’s Capitol Hill office, the United States Court of Appeals for the District of Columbia Circuit ruled, citing a principle that goes back hundreds of years, to the time of all-powerful English monarchs.
Accordingly, we hold that the congressman is entitled to the return of all legislative materials (originals and copies) that are protected by the Speech or Debate clause seized from Rayburn House Office Building...
The F.B.I. raid on Mr. Jefferson’s office was the first time a federal lawmaker’s office was searched in a criminal investigation. The incident ignited a debate that cut across party lines, with several members of Congress complaining that the executive branch was intruding on their domain.
Today’s ruling seems unlikely to derail the prosecution of Mr. Jefferson, who was indicted on June 4 on 16 felony counts charging that he put his office up for sale in hopes of reaping hundreds of thousands of dollars in bribes from nearly a dozen companies involved in oil, communications, sugar and other businesses, often for projects to be carried out in Africa. ...
The appeals court emphasized that the Speech or Debate Clause, while a formidable shield for lawmakers, is not an absolute one. The shield “does not extend beyond what is necessary to preserve the integrity of the legislative process,” and it “does not prohibit inquiry into illegal conduct simply becomes it has some nexus to legislative functions,” the court said, quoting Supreme Court language from a 1972 ruling.
There is not a lot of litigation concerning the "Speech or Debate Clause". I worked on one such, Davis v. Passman (concerning alleged sex discrimination by a Congressman against a female employee), while a law clerk; the case ultimately found its way to the Supreme Court.
So the question of the day: does the Speech or Debate clause protect The Dick (in his quasi-legislative capacity as President of the Senate) if he keeps illicit cash in his human-sized office (or residence) safes? (Rep. Jefferson apparently kept nearly $100,000 cash cooled in his home freezer--allegedly the proceeds of bribes.)