91384 leans slightly Republican by roughly 6 points: about 47% of voters vote Democratic and 53% Republican.
About 45% of adults in 91384 typically vote, below the U.S. average of about 62%. Among adults in 91384, ~21% vote Democratic, ~24% Republican, and ~55% don't vote. The map below shows estimated turnout by block group.
How 91384 compares
Among zip codes within 15 miles, 91384 leans more Republican than 9 of 11 neighbors.
91384 runs about 27 points more Republican than California as a whole. California leans Democratic overall, while 91384 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 91384. The southeast side runs the most Democratic (D+15) and the north side runs the most Republican (R+31), a spread of about 45 points.
Why 91384 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 91384, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 82% of households in 91384 are family households, about 16 points above the U.S. average of 67%. 91384 runs against the grain of California, a Republican-leaning pocket in a Democratic-leaning state.
High-school completion, developed land, and voter turnout
Places that combine low high-school-completion share and a heavily developed built environment tend to turn out at a lower rate, as 91384, CA does.
Why turnout in 91384 looks the way it does
Crowded housing lines up with lower turnout. About 4% of homes in 91384 have more than one occupant per room, above 81% 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.