Santa Rosa leans heavily Democratic by roughly 42 points: about 71% of voters vote Democratic and 29% Republican.
About 62% of adults in Santa Rosa typically vote, near the U.S. average of about 62%. Among adults in Santa Rosa, ~44% vote Democratic, ~18% Republican, and ~38% don't vote. The map below shows estimated turnout by block group.
How Santa Rosa compares
Among cities within 25 miles, Santa Rosa leans more Democratic than 29 of 49 neighbors.
Santa Rosa runs about 22 points more Democratic than California as a whole.
Politics vary noticeably by neighborhood within Santa Rosa. The east side is the most Democratic-leaning (D+51) and the southwest side is the least Democratic-leaning (D+33), a spread of about 18 points.
Why Santa Rosa 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 Santa Rosa, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 86% of residents in Santa Rosa live in densely developed areas, about 50 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Santa Rosa sits in the top quarter (about 34%, above 81% of cities). A high never-married share predicts Democratic voting, and about 35% of adults in Santa Rosa have never been married, above 87% of cities.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Santa Rosa, CA sits in the top tenth nationally on this measure.
Why turnout in Santa Rosa looks the way it does
Renters vote less often than owners. About 41% of households in Santa Rosa rent, about 16 points above the U.S. average of 25%. Crowded housing lines up with lower turnout, and about 7% of homes in Santa Rosa have more than one occupant per room, above 93% of cities. Low high-school completion lines up with lower turnout, and about 85% of adults in Santa Rosa have completed high school, below 81% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Fulton, CA D+28
- Rohnert Park, CA D+38
- Sebastopol, CA D+50
- Cotati, CA D+40
- Windsor, CA D+30
- Kenwood, CA D+53
- Graton, CA D+55
- Penngrove, CA D+27
- Forestville, CA D+53
- Glen Ellen, CA D+54
Cities with Similar Populations
- Moreno Valley, CA D+18
- Port St. Lucie, FL R+7
- Eugene, OR D+39
- Spring Valley, NV D+14
- Brownsville, TX Even
- Bradenton, FL R+14
- Murfreesboro, TN R+14
- Hialeah, FL R+42
- Shreveport, LA D+29
- Frisco, TX R+5
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.