Many of the current contenders either are members of, or have served in the US Senate (Hillary Clinton; Barack Obama; John Edwards; Joe Biden; Chris Dodd; Mike Gravel; Fred Thompson; John McCain; Sam Brownback). In the 1960s the candidates of both parties, & therefore the Presidents, had senatorial experience (John F Kennedy 1960; Lyndon Johnson 1964; Barry Goldwater 1964; Richard Nixon 1960, 1968; Hubert Humphrey 1968) - but there have been no Presidents who have served in the Senate since. However there have been a number of losing candidates! (Mondale; Gore; Kerry)