Castella leans Republican by roughly 22 points: about 39% of voters vote Democratic and 61% Republican.
About 69% of adults in Castella typically vote, above the U.S. average of about 62%. Among adults in Castella, ~27% vote Democratic, ~42% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How Castella compares
Among cities within 25 miles, Castella leans more Republican than 7 of 10 neighbors.
Castella runs about 43 points more Republican than California as a whole. California leans Democratic overall, while Castella is one of the few Republican-leaning pockets.
Why Castella leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Castella, not a ranked or complete list of what matters most.
Castella votes against the grain of California. California leans Democratic overall, while Castella runs about 43 points more Republican. Rural areas vote Republican, and Castella sits in the bottom quarter on density (about 3%, below 90% of cities).
Population density and Republican lean
Places with low population density tend to lean Republican; Castella, CA sits in the bottom tenth nationally on this measure.
Why turnout in Castella looks the way it does
Homeowners vote more often than renters. About 90% of households in Castella own their home, about 28 points above the California average of 62%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Sweetbriar, CA R+17
- Dunsmuir, CA Even
- Shasta Retreat, CA Even
- Mount Shasta, CA D+9
- Mccloud, CA R+16
- Lakehead, CA R+26
- Trinity Center, CA R+28
- Big Bend, CA R+36
- Weed, CA Even
Cities with Similar Populations
- Pentress, WV R+57
- Andover, SD R+42
- Telegraph, TX R+75
- Gooseneck, NC R+21
- Middle Run, WV R+58
- West Brooksville, ME D+22
- Mount Hope, WA R+56
- Maple Springs, NY R+30
- Meppen, IL R+54
- Saturn, TX R+64
All Local Stats
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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.