92521 leans heavily Democratic by roughly 48 points: about 74% of voters vote Democratic and 26% Republican.
About 26% of adults in 92521 typically vote, below the U.S. average of about 62%. Among adults in 92521, ~19% vote Democratic, ~7% Republican, and ~74% don't vote. The map below shows estimated turnout by block group.
How 92521 compares
Among zip codes within 15 miles, 92521 is the most Democratic-leaning.
92521 runs about 27 points more Democratic than California as a whole.
Why 92521 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 92521, not a ranked or complete list of what matters most.
Areas with many never-married adults vote Democratic. More than 99% of adults in 92521 have never been married, far above similar-sized zip codes (around 26%). Density combined with diversity predicts Democratic voting, and non-Hispanic white share in 92521 is about 14%, about 58 points below the U.S. average of 72%.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 92521, CA sits in the top quarter 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 92521 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 92521 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 33%, about 29 points below the California average of 62%. Renters vote less often than owners, and more than 99% of households in 92521 rent, compared to around 39% in nearby zip codes. High food insecurity lines up with lower turnout, and about 56% of adults in 92521 report food insecurity, in the top fraction 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.