In 1970, when he was just 36, Mr. Tunney ran for the Senate. He was blessed with a weak Republican opponent, the one-term incumbent Senator George Murphy, a former actor and song-and-dance man whose age — he was in his late 60s — and health were issues. Mr. Murphy was also hurt by the revelation that while a senator he had been paid $20,000 a year as a public relations consultant for a movie company.
Mr. Tunney’s victory margin in 1970 was bigger than that enjoyed by Ronald Reagan, who was re-elected California governor that year. Soon, Mr. Tunney was being mentioned as a possible running mate of Senator Edmund S. Muskie of Maine, who seemed to have the inside track for the Democratic nomination to run against President Richard M. Nixon in 1972. But the Maine senator’s campaign flamed out early in 1972.
That summer, Robert Redford starred in “The Candidate,” a film based on Mr. Tunney’s 1970 campaign, and the senator still appeared to have a bright future.