Custer leans heavily Republican by roughly 48 points: about 26% of voters vote Democratic and 74% Republican.
About 75% of adults in Custer typically vote, above the U.S. average of about 62%. Among adults in Custer, ~19% vote Democratic, ~55% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.
How Custer compares
Among cities within 25 miles, Custer leans more Republican than 6 of 12 neighbors.
Custer runs about 19 points more Republican than South Dakota as a whole.
Politics vary noticeably by neighborhood within Custer. The east side is the most Republican-leaning (R+55) and the west side is the least Republican-leaning (R+42), a spread of about 13 points.
Why Custer leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Custer. The lean here lands roughly where demographic data alone would predict.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; Custer, SD sits in the top quarter nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in Custer looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Custer is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 72%, about 12 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Sanator, SD R+52
- Pringle, SD R+55
- Hill City, SD R+41
- Keystone, SD R+46
- Fairburn, SD R+57
- Hermosa, SD R+58
- Minnekahta, SD R+53
- Silver City, SD R+42
- Buffalo Gap, SD R+53
Cities with Similar Populations
- Cajahs Mountain, NC R+53
- Aldan, PA D+40
- Juneau, WI R+40
- Lakeville, IN R+42
- Spearman, TX R+68
- Flagler Estates, FL R+58
- Montague, NJ R+35
- Haskell, TX R+58
- Venetian Village, IL D+6
- Rocky Top, TN R+61
All Local Stats
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Sources and methodology
Precinct-level voting records used to fit the model come from South Dakota 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.