Corson County, SD Political Map | Democrat & Republican Areas in Corson County

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

Corson County leans heavily Democratic by roughly 38 points: about 69% of voters vote Democratic and 31% Republican.

 

About 47% of adults in Corson County typically vote, below the U.S. average of about 62%. Among adults in Corson County, ~32% vote Democratic, ~15% Republican, and ~53% don't vote. The map below shows estimated turnout by block group.

How Corson County compares

Among counties within 50 miles, Corson County leans more Democratic than 4 of 5 neighbors.

Corson County runs about 67 points more Democratic than South Dakota as a whole. South Dakota leans Republican overall, while Corson County is one of the few Democratic-leaning pockets.

Politics vary noticeably by city within Corson County. The southeast side runs the most Democratic (D+61) and the west side runs the most Republican (R+69), a spread of about 130 points.

Why Corson County leans the way it does

This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Corson County, not a ranked or complete list of what matters most.

Corson County votes against the grain of South Dakota. South Dakota leans Republican overall, while Corson County runs about 67 points more Democratic. A high never-married share predicts Democratic voting, and about 46% of adults in Corson County have never been married, above 98% of counties.

Cancer-screening access and voter turnout

Places with low colon-cancer-screening access tend to turn out at a lower rate; Corson County, SD sits in the bottom tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.

Why turnout in Corson County looks the way it does

Areas with limited routine healthcare access turn out at lower rates. Corson County is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 48%, about 17 points below the South Dakota average of 66%. Renters vote less often than owners, and about 43% of households in Corson County rent, about 18 points above the U.S. average of 25%. High-crime urban areas turn out at lower rates, and Corson County sits in the top 15% on a violent-crime measure. Learn more about the findings and methodology on the political spectrum map.

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.