94904 is a Democratic stronghold. About 76% of voters here vote Democratic and 24% Republican.
About 81% of adults in 94904 typically vote, above the U.S. average of about 62%. Among adults in 94904, ~62% vote Democratic, ~19% Republican, and ~19% don't vote. The map below shows estimated turnout by block group.
How 94904 compares
Among zip codes within 15 miles, 94904 leans more Democratic than 20 of 54 neighbors.
94904 runs about 33 points more Democratic than California as a whole.
Why 94904 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 94904, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 73% of adults in 94904 hold a bachelor's degree, about 45 points above the U.S. average of 28%. Dense areas vote Democratic, and 94904 sits in the top fifth on density (about 90%, above 88% of zip codes).
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 94904, 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 94904 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 94904 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 77%, about 17 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and more than 99% of adults in 94904 have completed high school, above 98% 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.