Garamendi won election to the California State Assembly in 1974, representing most of Sacramento County as well as all or part of seven other counties to the east and south, and to the State Senate in 1976. He ran unsuccessfully in the 1982 Democratic gubernatorial primary, where he was defeated by Tom Bradley, and in the 1986 Democratic primary for California State Controller, when he lost to Gray Davis; but in 1990 he was successful in his campaign to become California's first Commissioner of Insurance, an office that brought him much controversy due to the state seizure of Executive Life Insurance Company, a bankruptcy that was coincidental with the creation of the state Department of Insurance.
Halfway through his term as Insurance Commissioner, on July 16, 2004, Garamendi announced his candidacy for the 2006 race to replace the term-limited Bustamante as Lieutenant Governor [4]. Bustamante had run to replace Garamendi as Insurance Commissioner.
Former Vice PresidentAl Gore had endorsed Garamendi for Lt. Governor. Garamendi was also endorsed by the Sierra Club, the California Teachers Association, the California League of Conservation Voters, the Peace Officers Research Association of California, the California Professional Firefighters Association, former Senate Majority Leader Tom Daschle and former Interior Secretary Bruce Babbitt, to name a few.
In the June 6, 2006 Democratic primary, Garamendi defeated state senators Liz Figueroa and Jackie Speier, receiving 43% of the vote. The margin of votes between Garamendi and Speier was very tight during much of the election night, with each receiving about 40% of the vote, but in later returns Garamendi pulled ahead. In November 2006 he faced Republican Tom McClintock and several candidates from smaller political parties in the general election. California elects governors and lieutenant governors separately; state treasurer Phil Angelides was the Democratic nominee for Governor, but Garamendi could not, in any formal sense, be called Angelides' running mate. Garamendi was elected Lieutenant Governor with 49% of the vote to 45% for Tom McClintock.