San Carlos is a Democratic stronghold. About 79% of voters here vote Democratic and 21% Republican.
About 77% of adults in San Carlos typically vote, above the U.S. average of about 62%. Among adults in San Carlos, ~61% vote Democratic, ~16% Republican, and ~23% don't vote. The map below shows estimated turnout by block group.
How San Carlos compares
Among cities within 25 miles, San Carlos leans more Democratic than 58 of 66 neighbors.
San Carlos runs about 37 points more Democratic than California as a whole.
Why San Carlos 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 San Carlos, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 71% of adults in San Carlos hold a bachelor's degree, about 42 points above the U.S. average of 28%. Dense areas vote Democratic, and San Carlos sits in the top fifth on density (about 92%, above 97% of cities).
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; San Carlos, CA sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in San Carlos looks the way it does
Areas with strong routine healthcare access turn out at higher rates. San Carlos 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 75%, about 15 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in San Carlos have completed high school, above 90% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Belmont, CA D+53
- Redwood City, CA D+53
- North Fair Oaks, CA D+49
- Foster City, CA D+50
- Woodside, CA D+46
- San Mateo, CA D+49
- Atherton, CA D+46
- Highlands-Baywood Park, CA D+52
- Menlo Park, CA D+64
- Hillsborough, CA D+41
Cities with Similar Populations
- Anthem, AZ R+24
- Dania Beach, FL D+10
- Greenville, MS D+57
- Atascadero, CA R+7
- Graham, WA R+21
- Crowley, TX R+10
- Grandville, MI R+5
- Lewis Center, OH D+8
- Fruit Cove, FL R+30
- Rockford, MI R+16
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.