Castle Rock leans Republican by roughly 30 points: about 35% of voters vote Democratic and 65% Republican.
About 84% of adults in Castle Rock typically vote, above the U.S. average of about 62%. Among adults in Castle Rock, ~29% vote Democratic, ~55% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How Castle Rock compares
Among cities within 25 miles, Castle Rock leans more Republican than 15 of 42 neighbors.
Castle Rock runs about 47 points more Republican than Washington as a whole. Washington leans Democratic overall, while Castle Rock is one of the few Republican-leaning pockets.
Why Castle Rock 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 Castle Rock, not a ranked or complete list of what matters most.
Castle Rock votes against the grain of Washington. Washington leans Democratic overall, while Castle Rock runs about 47 points more Republican. Dense places usually vote Democratic, but Castle Rock runs against that pattern.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Castle Rock, WA sits in the top quarter nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Castle Rock looks the way it does
Turnout in Castle Rock 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 Cities
- Silverlake, WA R+36
- Ostrander, WA R+36
- Eufaula Heights, WA R+27
- Vader, WA R+35
- Ryderwood, WA R+29
- Kelso, WA R+18
- Longview, WA R+9
- Sightly, WA R+40
- Toutle, WA R+40
- Toledo, WA R+41
Cities with Similar Populations
- Homer, AK R+6
- Kings Grant, NC R+4
- Kenilworth, NJ R+22
- Bishopville, SC D+20
- Tunkhannock, PA R+38
- Webster City, IA R+28
- Clearwater Beach, FL R+25
- Magee, MS R+27
- Bremen, IN R+44
- Akron, NY R+26
Sources and methodology
Precinct-level voting records used to fit the model come from Washington 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.