Sonoma leans heavily Democratic by roughly 48 points: about 74% of voters vote Democratic and 26% Republican.
About 68% of adults in Sonoma typically vote, above the U.S. average of about 62%. Among adults in Sonoma, ~50% vote Democratic, ~18% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How Sonoma compares
Among cities within 25 miles, Sonoma leans more Democratic than 42 of 60 neighbors.
Sonoma runs about 28 points more Democratic than California as a whole.
Politics vary noticeably by neighborhood within Sonoma. The southwest side is the most Democratic-leaning (D+55) and the southeast side is the least Democratic-leaning (D+43), a spread of about 12 points.
Why Sonoma leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Sonoma, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 71% of residents in Sonoma live in densely developed areas, about 34 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Sonoma sits in the top quarter (about 40%, above 87% of cities). A high never-married share predicts Democratic voting, and about 30% of adults in Sonoma have never been married, above 75% of cities.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; Sonoma, CA sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Sonoma looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Sonoma is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 68%, about 8 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Eldridge, CA D+44
- El Verano, CA D+43
- Schellville, CA D+33
- Glen Ellen, CA D+54
- Oakville, CA D+31
- Salvador, CA D+26
- Petaluma, CA D+42
- Napa, CA D+32
- Kenwood, CA D+53
- Yountville, CA D+32
Cities with Similar Populations
- Orangevale, CA R+10
- Bixby, OK R+23
- Litchfield Park, AZ R+9
- West Odessa, TX R+46
- Spring Valley, CA D+11
- Liberty, MO R+13
- Des Moines, WA D+31
- Pueblo West, CO R+28
- Tifton, GA R+12
- Santa Paula, CA D+21
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Sources and methodology
Precinct-level voting records used to fit the model come from California Secretary of State, Elections, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.