I've heard that the inland northern part of San Diego County for years was a hotbed of racist activity. It was the headquarters of Tom Metzger who actually won the nomination for a congressional seat in that area at one point.
1980 Democratic nomination. The Carter-Metzger ticket was defeated in the general election by Reagan-Burgener.
It's important to note that Democrats did not endorse Metzger and Governor Brown endorsed Burgener. Right-wingers can win in Dem primaries sometimes. Democratic does not always equal left-wing.