90277 leans heavily Democratic by roughly 32 points: about 66% of voters vote Democratic and 34% Republican.
About 73% of adults in 90277 typically vote, above the U.S. average of about 62%. Among adults in 90277, ~48% vote Democratic, ~25% Republican, and ~27% don't vote. The map below shows estimated turnout by block group.
How 90277 compares
Among zip codes within 15 miles, 90277 leans more Democratic than 16 of 78 neighbors.
90277 runs about 11 points more Democratic than California as a whole.
Politics vary noticeably by block within 90277. The west side is the most Democratic-leaning (D+44) and the south side is the least Democratic-leaning (D+23), a spread of about 21 points.
Why 90277 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 90277, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 92% of residents in 90277 live in densely developed areas, about 56 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 90277 sits in the top quarter (about 69%, above 97% of zip codes).
Population density and Democratic lean
Places with high population density tend to lean Democratic; 90277, CA sits in the top tenth nationally on this measure.
Why turnout in 90277 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 90277 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 74%, about 14 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in 90277 have completed high school, 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.