91711 leans heavily Democratic by roughly 36 points: about 68% of voters vote Democratic and 32% Republican.
About 65% of adults in 91711 typically vote, near the U.S. average of about 62%. Among adults in 91711, ~44% vote Democratic, ~21% Republican, and ~35% don't vote. The map below shows estimated turnout by block group.
How 91711 compares
Among zip codes within 15 miles, 91711 is the most Democratic-leaning.
91711 runs about 15 points more Democratic than California as a whole.
Politics vary noticeably by block within 91711. The southeast side is the most Democratic-leaning (D+52) and the northeast side is the least Democratic-leaning (D+19), a spread of about 33 points.
Why 91711 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 91711, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 61% of adults in 91711 hold a bachelor's degree, about 33 points above the U.S. average of 28%. Dense areas vote Democratic, and 91711 sits in the top fifth on density (about 93%, above 90% of zip codes). A high never-married share predicts Democratic voting, and about 40% of adults in 91711 have never been married, above 87% of zip codes.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 91711, 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 91711 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 91711 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 71%, about 11 points above the U.S. average of 60%. 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.