The 1966 California gubernatorial election was held on November 8, 1966. Incumbent Democratic Governor Pat Brown was defeated in his bid for re-election by Republican nominee and future President Ronald Reagan. As of , this remains the last time an incumbent governor of California lost re-election, though one subsequent governor was recalled from office in 2003.
Incumbent governor Pat Brown had been twice elected with significant accomplishments, such as the construction of the state highway system.
California's liberal Republicans including George Christopher leveled attacks on Ronald Reagan for his conservative positions. In response, Reagan popularized the eleventh commandment created by California Republican Party chairman Gaylord Parkinson. In his 1990 autobiography An American Life, Reagan attributed the rule to Parkinson, explained its origin, and claimed to have followed it, writing, "The personal attacks against me during the primary finally became so heavy that the state Republican chairman, Gaylord Parkinson, postulated what he called the Eleventh Commandment: Thou shalt not speak ill of any fellow Republican. It's a rule I followed during that campaign and have ever since." Parkinson used the phrase as common ground to prevent a split in the party.
Polls in February 1966 showed Christopher with a seven-point lead over Brown and Brown leading Reagan by four, so Brown sought to influence the Republican primary in Reagan's favor by having operatives pass negative claims against Christopher to columnist Drew Pearson.
With the nomination of Reagan, a well-known and charismatic political outsider-actor, the Republicans seized upon Brown's sudden unpopularity evidenced by a tough battle in the Democratic primary. Nixon worked tirelessly behind the scenes and Reagan trumpeted his law-and-order campaign message, going into the general election with a great deal of momentum. After pollsters discovered that the Berkeley student protests were a major priority of Republican voters, Reagan repeatedly promised to "clean up the mess at Berkeley".
At first, Brown tried to smear Reagan's conservative supporters with "lame Nazi metaphors". After Reagan deftly parried that tactic, Brown made a serious gaffe. He ran a television commercial in which he used a rhetorical question to remind a group of elementary school children that John Wilkes Booth, another actor, had killed Abraham Lincoln. Brown's crude comparison of Reagan to Booth based on their common background as actorsâÂÂin the state that happens to be home to HollywoodâÂÂdid not go over well with the California electorate. Brown won in only three counties, Alameda, Plumas, and San Francisco. He narrowly won Alameda by about 2,000 votes and Plumas by about 100 votes.