Which Bay Area county has the most Republicans? [View all]
http://blog.sfgate.com/ontheblock/2014/11/04/which-bay-area-county-has-the-most-republicans/
The Bay Area is known for its lefty leanings, but there are some Bay Area counties that are much bluer than others, according to a just-in-time-for-Election-Day report from Paragon Real Estate Group. It will likely come as a surprise to no one that San Francisco has the fewest registered Republicans in the Bay Areaonly 8.6% compared to 55.6% registered Democrats. (The remainder are third-party members and independents.)
Interestingly, Alameda County has even more registered Democrats (56.4%) but it also has more registered Republicans (14.1%). Heading north-eastward to Contra Costa County, the percentage of Republicans climbs dramatically to 24.8% with registered Democrats at 49.6%. But the award for highest percentage of Republicans in the Bay Area actually goes to Napa County, where 26.8% of residents are registered Republicans and only 46.4% of residents are Democrats. (The fewest registered Democrats45.6%are in Santa Clara.)
See the chart below for the breakdown throughout the rest of the Bay.

As the chart shows, Napa comes close to the percentage of registered Republicans in the U.S., though it also has far more registered Democrats than the national figures. As Paragon sums up in its report, despite some smatterings of red here and there, The Bay Area is a very blue region in a very blue state.