90027 is a Democratic stronghold. About 78% of voters here vote Democratic and 22% Republican.
About 55% of adults in 90027 typically vote, below the U.S. average of about 62%. Among adults in 90027, ~43% vote Democratic, ~12% Republican, and ~45% don't vote. The map below shows estimated turnout by block group.
How 90027 compares
Among zip codes within 15 miles, 90027 leans more Democratic than 133 of 162 neighbors.
90027 runs about 35 points more Democratic than California as a whole.
Politics vary noticeably by block within 90027. The east side is the most Democratic-leaning (D+72) and the southwest side is the least Democratic-leaning (D+39), a spread of about 34 points.
Why 90027 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 90027, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 90027 live in densely developed areas, about 64 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 90027 sits in the top quarter (about 60%, above 94% of zip codes). A high never-married share predicts Democratic voting, and about 50% of adults in 90027 have never been married, above 95% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 90027, CA sits in the top tenth nationally on this measure.
Why turnout in 90027 looks the way it does
Renters vote less often than owners. About 79% of households in 90027 rent, about 54 points above the U.S. average of 25%. Crowded housing lines up with lower turnout, and about 7% of homes in 90027 have more than one occupant per room, above 91% 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.