Mellette County leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 48% of adults in Mellette County typically vote, below the U.S. average of about 62%. Among adults in Mellette County, ~18% vote Democratic, ~30% Republican, and ~52% don't vote. The map below shows estimated turnout by block group.
How Mellette County compares
Among counties within 50 miles, Mellette County leans more Republican than 2 of 3 neighbors.
Mellette County runs about 5 points more Democratic than South Dakota as a whole.
Politics vary noticeably by city within Mellette County. The southeast side is the most Republican-leaning (R+37) and the northwest side is the least Republican-leaning (R+12), a spread of about 26 points.
Why Mellette 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 Mellette County, not a ranked or complete list of what matters most.
Rural areas vote Republican. About 1% of residents in Mellette County live in densely developed areas, about 8 points below the South Dakota average of 9%.
Walkability and Republican lean
Places with a low walkability score tend to lean Republican; Mellette County, SD sits in the bottom tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Mellette County looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Mellette 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 46%, about 20 points below the South Dakota average of 66%. Renters vote less often than owners, and about 40% of households in Mellette County rent, about 15 points above the U.S. average of 25%. High-crime urban areas turn out at lower rates, and Mellette County sits in the top 15% on a violent-crime measure. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Todd County, SD D+57
- Jones County, SD R+72
- Jackson County, SD R+9
- Tripp County, SD R+58
- Cherry County, NE R+67
- Bennett County, SD R+7
- Haakon County, SD R+71
- Stanley County, SD R+49
- Lyman County, SD R+5
- Hughes County, SD R+34
Counties with Similar Populations
- Meagher County, MT R+58
- Gosper County, NE R+72
- Buffalo County, SD D+24
- Liberty County, MT R+56
- Oliver County, ND R+67
- Logan County, ND R+75
- Garden County, NE R+70
- Menard County, TX R+53
- Haakon County, SD R+71
- Sherman County, OR R+59
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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.