90704 leans Democratic by roughly 16 points: about 58% of voters vote Democratic and 42% Republican.
About 58% of adults in 90704 typically vote, near the U.S. average of about 62%. Among adults in 90704, ~34% vote Democratic, ~24% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.
How 90704 compares
Politically, 90704 sits close to the rest of California.
Why 90704 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 90704, not a ranked or complete list of what matters most.
Areas with many never-married adults vote Democratic. About 34% of adults in 90704 have never been married, modestly above similar-sized zip codes (around 27%).
Park access and Democratic lean
Places with heavy park coverage tend to lean Democratic; 90704, CA sits in the top quarter nationally on this measure. Park access does not change how people vote; it tends to track denser, higher-income areas.
Why turnout in 90704 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 90704 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 48% of households in 90704 rent, about 23 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 21% of adults in 90704 report food insecurity, above 81% 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.