Colma leans heavily Democratic by roughly 40 points: about 70% of voters vote Democratic and 30% Republican.
About 50% of adults in Colma typically vote, below the U.S. average of about 62%. Among adults in Colma, ~35% vote Democratic, ~15% Republican, and ~50% don't vote. The map below shows estimated turnout by block group.
How Colma compares
Among cities within 25 miles, Colma leans more Democratic than 13 of 76 neighbors.
Colma runs about 19 points more Democratic than California as a whole.
Why Colma 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 Colma, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 98% of residents in Colma live in densely developed areas, about 62 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 40% of adults in Colma have never been married, above 93% of cities.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Colma, CA sits in the top tenth nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Colma looks the way it does
Renters vote less often than owners. About 53% of households in Colma rent, about 28 points above the U.S. average of 25%. Crowded housing lines up with lower turnout, and about 12% of homes in Colma have more than one occupant per room, above 98% of cities. Low high-school completion lines up with lower turnout, and about 81% of adults in Colma have completed high school, below 89% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Daly City, CA D+39
- South San Francisco, CA D+43
- Brisbane, CA D+50
- Pacifica, CA D+43
- San Bruno, CA D+43
- San Francisco, CA D+48
- Millbrae Meadows, CA D+33
- Millbrae, CA D+40
- Pedro Valley, CA D+32
- Burlingame, CA D+52
Cities with Similar Populations
- Sea Isle City, NJ R+18
- Darby, MT R+49
- St. Elmo, AL R+58
- Dilkon, AZ D+51
- Quaker City, OH R+66
- Huron, TN R+73
- Cool Ridge, WV R+66
- Mesopotamia, OH R+56
- Rockdale, IL D+4
- West River, MD R+14
All Local Stats
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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.