Castleford is a Republican stronghold. About 15% of voters here vote Democratic and 85% Republican.
About 62% of adults in Castleford typically vote, near the U.S. average of about 62%. Among adults in Castleford, ~9% vote Democratic, ~53% Republican, and ~38% don't vote. The map below shows estimated turnout by block group.
How Castleford compares
Among cities within 25 miles, Castleford leans more Republican than 12 of 13 neighbors.
Castleford runs about 35 points more Republican than Idaho as a whole.
Why Castleford 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 Castleford, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 76% of households in Castleford are family households, about 9 points above the U.S. average of 67%.
Population density and Republican lean
Places with low population density tend to lean Republican; Castleford, ID sits below the national average on this measure.
Why turnout in Castleford looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Castleford is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Fairview, ID R+70
- Deep Creek, ID R+68
- Buhl, ID R+56
- Clover, ID R+68
- Filer, ID R+58
- Hollister, ID R+70
- Wendell, ID R+53
- Hagerman, ID R+63
- Twin Falls, ID R+36
- Falls City, ID R+61
Cities with Similar Populations
- Stanley, IA R+43
- Salem Center, IN R+56
- West Bainbridge, GA R+58
- Stephens, GA R+58
- New Amsterdam, IN R+58
- New Burlington, OH R+59
- Woodwards, MS R+26
- Stilson, GA R+59
- Broadview, MT R+58
- Bruno, MN R+33
Sources and methodology
Precinct-level voting records used to fit the model come from Idaho 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.