91301 leans Democratic by roughly 18 points: about 59% of voters vote Democratic and 41% Republican.
About 80% of adults in 91301 typically vote, above the U.S. average of about 62%. Among adults in 91301, ~47% vote Democratic, ~33% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How 91301 compares
Among zip codes within 15 miles, 91301 leans more Democratic than 13 of 30 neighbors.
Politically, 91301 sits close to the rest of California.
Politics vary noticeably by block within 91301. The west side is the most Democratic-leaning (D+24) and the south side is the least Democratic-leaning (D+3), a spread of about 21 points.
Why 91301 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 91301, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 66% of adults in 91301 hold a bachelor's degree, about 37 points above the U.S. average of 28%. Dense areas vote Democratic, and 91301 sits in the top fifth on density (about 74%, above 81% of zip codes).
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 91301, CA sits in the top tenth 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 91301 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 91301 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 76%, about 16 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in 91301 have completed high school, above 88% 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.