Berryessa leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.
About 54% of adults in Berryessa typically vote, below the U.S. average of about 62%. Among adults in Berryessa, ~33% vote Democratic, ~21% Republican, and ~46% don't vote. The map below shows estimated turnout by block group.
How Berryessa compares
Among neighborhoods within 5 miles, Berryessa is the least Democratic-leaning.
Politically, Berryessa sits close to the rest of California.
Why Berryessa leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Berryessa. The lean here lands roughly where demographic data alone would predict.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Berryessa, San Jose, CA sits in the top quarter nationally on this measure.
Why turnout in Berryessa looks the way it does
Crowded housing lines up with lower turnout. About 6% of homes in Berryessa have more than one occupant per room, above 82% of neighborhoods. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
- North Valley, San Jose, CA D+27
- East Foothills, San Jose, CA D+27
- North San Jose, San Jose, CA D+41
- Naglee Park, San Jose, CA D+53
- Downtown San Jose, San Jose, CA D+47
- East San Jose, San Jose, CA D+27
- Rose Garden, San Jose, CA D+46
- Alma, San Jose, CA D+36
- Burbank, San Jose, CA D+41
- Garden-Villa Montery, San Jose, CA D+33
Neighborhoods with Similar Populations
- Scripps Ranch, San Diego, CA D+20
- Torresdale, Philadelphia, PA R+10
- West End, Tacoma, WA D+33
- North Lawndale, Chicago, IL D+78
- Rhodes Ranch, Spring Valley, NV D+12
- Old Brooklyn, Cleveland, OH D+14
- Ettingville, Staten Island, NY R+54
- Payne Phallen, St. Paul, MN D+40
- Carrollwood, Tampa, FL R+5
- Wrigley, Long Beach, CA D+42
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.