94591 leans heavily Democratic by roughly 34 points: about 67% of voters vote Democratic and 33% Republican.
About 55% of adults in 94591 typically vote, below the U.S. average of about 62%. Among adults in 94591, ~37% vote Democratic, ~18% Republican, and ~45% don't vote. The map below shows estimated turnout by block group.
How 94591 compares
Among zip codes within 15 miles, 94591 leans more Democratic than 7 of 27 neighbors.
94591 runs about 14 points more Democratic than California as a whole.
Politics vary noticeably by block within 94591. The northwest side is the most Democratic-leaning (D+42) and the northeast side is the least Democratic-leaning (D+26), a spread of about 16 points.
Why 94591 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 94591, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 86% of residents in 94591 live in densely developed areas, about 50 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 36% of adults in 94591 have never been married, above 81% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 94591, CA sits in the top tenth nationally on this measure.
Why turnout in 94591 looks the way it does
Crowded housing lines up with lower turnout. About 5% of homes in 94591 have more than one occupant per room, above 85% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
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.