95991 leans Republican by roughly 16 points: about 42% of voters vote Democratic and 58% Republican.
About 50% of adults in 95991 typically vote, below the U.S. average of about 62%. Among adults in 95991, ~21% vote Democratic, ~29% Republican, and ~50% don't vote. The map below shows estimated turnout by block group.
How 95991 compares
Among zip codes within 15 miles, 95991 leans more Republican than 3 of 9 neighbors.
95991 runs about 36 points more Republican than California as a whole. California leans Democratic overall, while 95991 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 95991. The southwest side is the most Republican-leaning (R+26) and the east side is the least Republican-leaning (R+6), a spread of about 21 points.
Why 95991 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 95991, not a ranked or complete list of what matters most.
95991 votes Republican even though it is densely developed (about 85%, well above the California average of 58%). State and regional patterns outweigh the Democratic lean that density usually predicts here. 95991 runs against the grain of California, a Republican-leaning pocket in a Democratic-leaning state.
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; 95991, CA sits below the national average 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 95991 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 95991 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 46% of households in 95991 rent, about 22 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 24% of adults in 95991 report food insecurity, above 87% 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.