94548 leans slightly Republican by roughly 14 points: about 43% of voters vote Democratic and 57% Republican.
About 31% of adults in 94548 typically vote, below the U.S. average of about 62%. Among adults in 94548, ~13% vote Democratic, ~18% Republican, and ~69% don't vote. The map below shows estimated turnout by block group.
How 94548 compares
Among zip codes within 15 miles, 94548 leans more Republican than 9 of 13 neighbors.
94548 runs about 34 points more Republican than California as a whole. California leans Democratic overall, while 94548 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 94548. The southwest side is the most Republican-leaning (R+33) and the east side is the least Republican-leaning (R+10), a spread of about 23 points.
Why 94548 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 94548, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 87% of households in 94548 are family households, about 21 points above the U.S. average of 67%. 94548 runs against the grain of California, a Republican-leaning pocket in a Democratic-leaning state.
Cancer-screening access and voter turnout
Places with low colon-cancer-screening access tend to turn out at a lower rate; 94548, 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 94548 looks the way it does
Crowded housing lines up with lower turnout. About 10% of homes in 94548 have more than one occupant per room, above 96% 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.