91935 leans heavily Republican by roughly 34 points: about 33% of voters vote Democratic and 67% Republican.
About 59% of adults in 91935 typically vote, near the U.S. average of about 62%. Among adults in 91935, ~20% vote Democratic, ~39% Republican, and ~41% don't vote. The map below shows estimated turnout by block group.
How 91935 compares
Among zip codes within 15 miles, 91935 is the most Republican-leaning.
91935 runs about 54 points more Republican than California as a whole. California leans Democratic overall, while 91935 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 91935. The northeast side is the most Republican-leaning (R+44) and the southwest side is the least Republican-leaning (R+27), a spread of about 17 points.
Why 91935 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 91935, not a ranked or complete list of what matters most.
91935 votes against the grain of California. California leans Democratic overall, while 91935 runs about 54 points more Republican. A high family-household share predicts Republican voting, and about 81% of households in 91935 are family households, above 92% of zip codes.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 91935, CA sits in the top quarter nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in 91935 looks the way it does
Turnout in 91935 sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. 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.