The 1966 California gubernatorial election was held on November 8, 1966. The election was a contest primarily between incumbent governor Pat Brown and former actor Ronald Reagan, who mobilized conservative voters and defeated Brown in a landslide. As of the 2022 gubernatorial election, this is the last time an incumbent Governor of California lost re-election. Background Incumbent governor Pat Brown had been relatively popular. After his re-election victory over former vice president Richard Nixon in 1962, Brown was strongly considered for Lyndon B. Johnson's running mate in 1964. However, Brown's popularity began to sag amidst the civil disorders of the Watts riots and the early student protests at the University of California, Berkeley including the Free Speech Movement. His decision to seek a third term as governor after promising earlier that he would not do so also hurt his popularity. Primaries California's liberal Republicans including George Christopher leveled attacks on Ronald Reagan for his conservative positions. 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 and the liberals eventually followed his advice. Results Campaign 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." Brown initially ran a low-key campaign, declaring that running the state was his biggest priority. Reagan's lead in the polls increased and Brown began to panic. Brown made a serious gaffe by running a television commercial in which he used a rhetorical question to remind a group of school children that John Wilkes Booth, another actor, killed Abraham Lincoln. The