Dole 1996 and Bush Jr. 2000 & 2004 won San Diego County.
Los Angeles County is a better bellwheter. It voted against the state only in 1976 and 1988.
Obama won San Diego in 2008 and 2012, but this county is still much more Republican than the average of the state.
Some northern counties are anti-bellwheter. They were Democratic in the past and Republican in the present.
And 1960, it voted for JFK not Nixon...even though that wasn't figured out until absentee ballots were counted.
Those inland Northern counties are culturally a lot like the South, that's why most of those counties have been GOP leaning only since 1980. That's why McGovern won more counties than Carter.
Well except for Alpine Co. which plays out more like a Vermont.
It voted for Nixon. NV voted for JFK that year. LBJ won California in 1964, but with a smaller lead than in the national PV (59%).
