Castaic, CA Political Map | Democrat & Republican Areas in Castaic

By the BestNeighborhood data science team. Last updated May 2026.

Castaic leans slightly Republican by roughly 6 points: about 47% of voters vote Democratic and 53% Republican.

 

About 45% of adults in Castaic typically vote, below the U.S. average of about 62%. Among adults in Castaic, ~21% vote Democratic, ~24% Republican, and ~55% don't vote. The map below shows estimated turnout by block group.

How Castaic compares

Among cities within 25 miles, Castaic leans more Republican than 38 of 49 neighbors.

Castaic runs about 27 points more Republican than California as a whole. California leans Democratic overall, while Castaic is one of the few Republican-leaning pockets.

Politics vary noticeably by neighborhood within Castaic. The east side runs the most Democratic (D+14) and the west side runs the most Republican (R+29), a spread of about 43 points.

Why Castaic 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 Castaic, not a ranked or complete list of what matters most.

Castaic votes Republican even though it is densely developed (about 37%, well below the California average of 58%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 83% of households in Castaic are family households, above 94% of cities. Castaic 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 Castaic, CA does.

Why turnout in Castaic looks the way it does

Crowded housing lines up with lower turnout. About 4% of homes in Castaic have more than one occupant per room, above 83% of cities. Learn more about the findings and methodology on the political spectrum map.

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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.