91945 leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.
About 57% of adults in 91945 typically vote, near the U.S. average of about 62%. Among adults in 91945, ~34% vote Democratic, ~22% Republican, and ~44% don't vote. The map below shows estimated turnout by block group.
How 91945 compares
Among zip codes within 15 miles, 91945 leans more Democratic than 24 of 55 neighbors.
Politically, 91945 sits close to the rest of California.
Politics vary noticeably by block within 91945. The north side is the most Democratic-leaning (D+30) and the southeast side is the least Democratic-leaning (D+17), a spread of about 13 points.
Why 91945 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 91945, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 91945 live in densely developed areas, about 64 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 38% of adults in 91945 have never been married, above 84% of zip codes.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 91945, CA sits in the top tenth 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 91945 looks the way it does
Areas with high food insecurity turn out at lower rates. About 21% of adults in 91945 report food insecurity, above 81% of zip codes. Renters vote less often than owners, and about 41% of households in 91945 rent, about 16 points above the U.S. average of 25%. 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.