The Socialist Workers Party is the latest of the Socialist parties to be active in California, having been founded in 1938. The SWP was created after members were expelled from the Socialist party for their support of Leon Trotsky. The SWP was particularly active in California between 1964 and 1976. The party ran four significant candidates; Susan Vass for Congress in San Francisco, and three candidates for President.
The most successfull SWP candidate in California was Peter Miguel Camejo, who received more than 17 thousand votes statewide during his 1976 Presidential campaign (no other SWP candidate received more than 600 votes. Starting in 1982, the SWP moved away from its Trotskyist position, and lost nearly a third of their membership who opposed the move. As of the 2004 elections, the SWP was on the ballot in 14 states.