South Bay leans slightly Democratic by roughly 14 points: about 57% of voters vote Democratic and 43% Republican.
About 66% of adults in South Bay typically vote, near the U.S. average of about 62%. Among adults in South Bay, ~38% vote Democratic, ~28% Republican, and ~34% don't vote. The map below shows estimated turnout by block group.
How South Bay compares
Among neighborhoods within 5 miles, South Bay is the least Democratic-leaning.
South Bay runs about 6 points more Republican than California as a whole.
Politics vary noticeably by block within South Bay. The northeast side is the most Democratic-leaning (D+22) and the southwest side is the least Democratic-leaning (D+2), a spread of about 19 points.
Why South Bay leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in South Bay. The lean here lands roughly where demographic data alone would predict.
Developed land and Republican lean
Places with a rural land-use pattern tend to lean Republican; South Bay, Eureka, CA sits in the bottom quarter nationally on this measure. Developed land does not change how people vote; it mostly reflects how urban a place is.
Why turnout in South Bay looks the way it does
Turnout in South Bay sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. Learn more about the findings and methodology on the political spectrum map.
Nearby Neighborhoods
- Cutten, Eureka, CA D+16
- The West Side, Eureka, CA D+37
- Old Town, Eureka, CA D+38
- Jacoby Creek, Arcata, CA D+59
- Rohnerville, Fortuna, CA D+6
- Happy Valley, Anderson, CA R+43
- Enterprise, Redding, CA R+13
- Starview, Redding, CA R+27
- Columbia, Redding, CA R+35
- Pacheco, Redding, CA R+39
Neighborhoods with Similar Populations
- East Elmhurst, Queens, NY R+11
- Greenwood, Newport News, VA D+38
- Five Mile Prairie, Spokane, WA R+13
- Crystal City, Arlington, VA D+59
- Bloomfield, Staten Island, NY R+37
- University Square, Tampa, FL D+36
- Windsor Forest, Savannah, GA D+24
- Bayshore Beautiful, Tampa, FL R+5
- South Park, Buffalo, NY D+7
- Sunrise, San Antonio, TX D+30
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.