95420 leans heavily Democratic by roughly 42 points: about 71% of voters vote Democratic and 29% Republican.
About 72% of adults in 95420 typically vote, above the U.S. average of about 62%. Among adults in 95420, ~51% vote Democratic, ~21% Republican, and ~28% don't vote. The map below shows estimated turnout by block group.
How 95420 compares
Among zip codes within 15 miles, 95420 leans more Democratic than 1 of 5 neighbors.
95420 runs about 22 points more Democratic than California as a whole.
Politics vary noticeably by block within 95420. The north side is the most Democratic-leaning (D+49) and the southeast side is the least Democratic-leaning (D+36), a spread of about 12 points.
Why 95420 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 95420. The lean here lands roughly where demographic data alone would predict.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 95420, 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 95420 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 95420 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 69%, about 9 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and more than 99% of adults in 95420 have completed high school, above 98% 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.