91905 leans Republican by roughly 28 points: about 36% of voters vote Democratic and 64% Republican.
About 37% of adults in 91905 typically vote, below the U.S. average of about 62%. Among adults in 91905, ~13% vote Democratic, ~24% Republican, and ~63% don't vote. The map below shows estimated turnout by block group.
How 91905 compares
Among zip codes within 15 miles, 91905 is the least Republican-leaning.
91905 runs about 47 points more Republican than California as a whole. California leans Democratic overall, while 91905 is one of the few Republican-leaning pockets.
Why 91905 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 91905, not a ranked or complete list of what matters most.
91905 votes against the grain of California. California leans Democratic overall, while 91905 runs about 47 points more Republican. Rural areas vote Republican, and 91905 sits in the bottom quarter on density (about 2%, below 97% of zip codes). A high family-household share predicts Republican voting, and about 74% of households in 91905 are family households, above 77% of zip codes.
Population density and Republican lean
Places with low population density tend to lean Republican; 91905, CA sits in the bottom quarter nationally on this measure.
Why turnout in 91905 looks the way it does
Areas with high food insecurity turn out at lower rates. About 24% of adults in 91905 report food insecurity, about 8 points above the U.S. average of 16%. 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.