90401 leans heavily Democratic by roughly 50 points: about 75% of voters vote Democratic and 25% Republican.
About 60% of adults in 90401 typically vote, near the U.S. average of about 62%. Among adults in 90401, ~45% vote Democratic, ~15% Republican, and ~40% don't vote. The map below shows estimated turnout by block group.
How 90401 compares
Among zip codes within 15 miles, 90401 leans more Democratic than 67 of 113 neighbors.
90401 runs about 29 points more Democratic than California as a whole.
Politics vary noticeably by block within 90401. The northeast side is the most Democratic-leaning (D+61) and the northwest side is the least Democratic-leaning (D+41), a spread of about 20 points.
Why 90401 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 90401, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 92% of residents in 90401 live in densely developed areas, about 56 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 90401 sits in the top quarter (about 76%, above 98% of zip codes). A high never-married share predicts Democratic voting, and about 56% of adults in 90401 have never been married, above 97% of zip codes.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 90401, 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 90401 looks the way it does
Renters vote less often than owners. About 94% of households in 90401 rent, about 69 points above the U.S. average of 25%. Strong routine healthcare access lines up with higher turnout, and 90401 sits in the top quarter on routine-care measures. 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.