Politics in the San Francisco Bay Area is widely regarded as one of the most liberal in the country. According to the California Secretary of State, the Democratic Party holds a voter registration advantage in every congressional district, State Senate district, State Assembly district, State Board of Equalization district, County Board of Supervisors district, all nine counties, and all of the 101 incorporated municipalities in the Bay Area. The Republican Party holds a voter registration advantage in one congressional sub-district (the portion of the 9th in Contra Costa County) and unincorporated Solano County.

Since 1960, the nine-county Bay Area has voted for Republican presidential candidates only twice: in 1972 for Richard Nixon and in 1980 for Ronald Reagan, both Californians. The last county to vote for a Republican presidential candidate was Napa County in 1988 for George H. W. Bush.

County-level statistics All nine counties in the Bay Area currently have a voter registration advantage in favor of the Democratic Party.

County Population (2020) 2024 election results Median household income (2018) Per capita income (2011)Voter Registration (2023) Democratic Independent Republican Alameda 1,682,296 74.6%—21.0% Harris $92,574 $33,888563,864 222,019 102,953 Contra Costa 1,165,983 67.3%-29.4% Harris $93,712 $36,274379,524 153,822 127,752 Marin 262,325 80.6%-16.7% Harris $110,217 $49,439106,921 33,102 20,721 Napa 138,014 65.9%-31.1% Harris $84,753 $32,17042,491 16,988 17,731 San Francisco 878,392 80.3%-15.5% Harris $104,552 $44,905318,286 122,624 34,890 San Mateo 764,659 73.5%-23.2% Harris $113,776 $44,331244,946 104,646 60,259 Santa Clara 1,936,278 68.0%-28.1% Harris $116,178 $39,365525,176 280,493 167,840 Solano 453,551 60.0%-37.0% Harris $77,609 $27,785129,593 57,895 58,542 Sonoma 488,862 71.4%-25.2% Harris $76,753 $30,868171,744 53,578 52,658 Median — — $96,265 $37,851 — — — Total 7,770,360 70.1%–24.2% Harris — —2,482,545 1,342,167 643,346 Counties by population and voter registration County PopulationU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B02001. U.S. Census website. Retrieved October 26, 2013. Registered votersCalifornia Secretary of State. Report of Registration as of February 10, 2017. Democratic Republican D–R spread AmericanIndependent Green Libertarian Peace andFreedom AmericansElect Other No party preference Alameda 1,494,876 54.6% 56.4% 14.1% +42.3% 2.0% 1.2% 0.5% 0.4% 0.0% 6.0% 19.5% Contra Costa 1,037,817 58.5% 50.4% 21.8% +24.8% 2.6% 0.5% 0.6% 0.2% 0.0% 0.2% 23.7% Marin 250,666 61.5% 54.4% 18.2% +36.2% 2.1% 1.4% 0.5% 0.2% 0.0% 0.3% 12.9% Napa 135,377 56.2% 46.9% 24.2% +22.7% 3.0% 0.8% 0.8% 0.3% 0.0% 0.5% 23.4% San Francisco 870,887 62.4% 55.6% 8.6% +47.0% 1.8% 1.7% 0.6% 0.3% 0.0% 0.3% 31.1% San Mateo 711,622 50.7% 51.3% 19.4% +31.9% 2.1% 0.7% 0.5% 0.2% 0.0% 0.2% 25.5% Santa Clara 1,762,754 46.5% 45.6% 21.7% +23.9% 2.1% 0.5% 0.6% 0.2% 0.0% 0.2% 29.0% Solano 411,620 51.1% 48.6% 25.0% +23.6% 2.8% 0.4% 0.5% 0.4% 0.0% 0.4% 22.0% Sonoma 478,551 54.7% 51.5% 21.6% +29.9% 2.5% 1.8% 0.7% 0.3% 0.0% 0.3% 21.3%

Congressional districts Every Congressional district in the Bay Area is currently represented by a Democrat. According to the Cook Partisan Voting Index (CPVI), congressional districts the Bay Area tends to favor Democratic candidates by roughly 40 to 50 percentage points, considerably above the mean for California and the nation overall. All congressional districts in the region voted for Democrat Kamala Harris over Republican Donald Trump in the 2024 Presidential Election.

District Location Representative Cook PVI 2024 election results Median household income (2025) 2nd Marin County and the North Coast D+24 70.9%–25.7% Harris $97,004 4th Lake and Napa, most of Yolo, and parts of Solano and Sonoma D+17 64.0%–32.8% Harris $98,067 8th Parts of Solano and Contra Costa around the Sacramento-San Joaquin River Delta D+24 70.1%-26.6% Harris $95,876 10th Most of Contra Costa: Concord, Southern Antioch, Walnut Creek and parts of Alameda, California D+18 65.2%-31.4% Harris $151,546 11th San Francisco D+36 81.4%–14.1% Harris $142,524 12th Berkeley, Oakland, and San Leandro D+39 84.5% 10.6% Harris $111,408 14th Hayward, Union City, and the Tri-Valley D+20 65.8%-30.3% Harris $137,402 15th Most of San Mateo County and southern San Francisco D+27 72.2%-24.3% Harris $151,494 16th From Pacifica to the southern edge of San Jose through Menlo Park and western Silicon Valley D+26 72.5%-23.9% Harris $181,659 17th South of Fremont and northern Silicon Valley D+25 66.7%-28.8% Harris $181,913 18th San Jose and Morgan Hill D+23 63.2%-33.7% Harris $103,010 Median — — D+19 72%–25% Harris $69,316

During the Base Realignment and Closures (BRACs) of the 1990s, almost all the military installations in the region were closed. The only remaining major active duty military installations are Travis Air Force Base and Coast Guard Island.

See also

San Francisco Public Pressure Groups Politics of San Francisco

References