On February 7, 1973, the Senate voted 70 to 0 to establish a seven-man committee, headed by Senator Sam Ervin (1896-1985), a Democrat from North Carolina, to probe the Watergate case. Televised hearings of the Senate Select Committee to Investigate Presidential Campaign Practices (commonly referred to as the Watergate committee, or the Ervin committee) were broadcast daily on national television. The hearings often produced dramatic moments, and they were widely watched. The Ervin committee's televised hearings climaxed in the stunning testimony of White House counsel John Dean, which implicated President Richard Nixon in the Watergate cover-up. Even more damaging was the public testimony of White House aide Alexander Butterfield on July 16, 1973. He revealed the existence of a secret recording system installed in the White House.

An ongoing battle over the tapes ensued: the Senate Committee, special prosecutor Archibald Cox (hired by the Justice Department to conduct an independent...