91023 is a true toss-up. About 51% of voters here vote Democratic and 49% Republican.
About 28% of adults in 91023 typically vote, below the U.S. average of about 62%. Among adults in 91023, ~14% vote Democratic, ~14% Republican, and ~72% don't vote. The map below shows estimated turnout by block group.
How 91023 compares
Among zip codes within 15 miles, 91023 sits roughly in the middle of the political spectrum, with 2 neighbors leaning further in the place's direction and 47 leaning the other way.
91023 runs about 19 points more Republican than California as a whole.
Why 91023 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 91023. The lean here lands roughly where demographic data alone would predict.
Cancer-screening access and voter turnout
Places with low colon-cancer-screening access tend to turn out at a lower rate; 91023, CA sits in the bottom quarter nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 91023 looks the way it does
Areas with low high-school completion turn out at lower rates. About 75% of adults in 91023 have completed high school, about 15 points below the U.S. average of 90%. 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.