Frank Church

Watergate made it easy for a Democrat to investigate a Republican White House. What Church's Senate committee did in 1975 and 1976 was harder: it documented decades of abuses by the CIA, FBI and National Security Agency under presidents of both parties, including the FBI's campaign against Martin Luther King and CIA assassination plots under Eisenhower and Kennedy, a Democratic icon. Church called the NSA's capabilities a potential "abyss from which there is no return". The committee's work led directly to the Foreign Intelligence Surveillance Act of 1978 and permanent congressional intelligence committees.