The Eleventh Commandment (Ronald Reagan)

While popularized by Reagan, "The Eleventh Commandment" was 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:[3]

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.

The goal was to prevent a repetition of the liberal Republican assault on Barry Goldwater, attacks which contributed to Goldwater's defeat in the 1964 presidential election.[1] East Coast Republicans like Nelson Rockefeller labeled Goldwater an "extremist" for his conservative positions and declared him unfit to hold office.[1] Fellow Republican candidate for Governor George Christopher and California's liberal Republicans were leveling similar attacks on Reagan. Hoping to prevent a split in the Republican Party, Parkinson used the phrase as common ground. Party liberals eventually followed Parkinson's advice.[1]

Christopher would lose to Reagan in the Republican primary, and Reagan would go on to defeat incumbent Governor Pat Brown, the father of future California Governor Jerry Brown.

Reagan followed this "commandment" during the first five primaries during the 1976 Republican primary against incumbent Gerald Ford, all of which he lost. He abandoned this approach in the North Carolina Primary and beat Ford 52–46, regaining momentum and winning a majority of delegates chosen after that date. Former Texas governor John Connally speculated that Reagan's attacks weakened Ford in the general election against his opponent and eventual successor, Jimmy Carter.[1]