Millboro is a Republican stronghold. About 13% of voters here vote Democratic and 87% Republican.
About 62% of adults in Millboro typically vote, near the U.S. average of about 62%. Among adults in Millboro, ~8% vote Democratic, ~54% Republican, and ~38% don't vote. The map below shows estimated turnout by block group.
How Millboro compares
Among cities within 25 miles, Millboro leans more Republican than 8 of 10 neighbors.
Millboro runs about 44 points more Republican than South Dakota as a whole.
Why Millboro 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 Millboro, not a ranked or complete list of what matters most.
Rural areas vote Republican. About 3% of residents in Millboro live in densely developed areas, about 7 points below the South Dakota average of 9%.
Population density and Republican lean
Places with low population density tend to lean Republican; Millboro, SD sits in the bottom tenth nationally on this measure.
Why turnout in Millboro looks the way it does
Areas with high high-school completion turn out at higher rates. About 98% of adults in Millboro have completed high school, about 6 points above the South Dakota average of 92%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Colome, SD R+71
- Keyapaha, SD R+31
- Springview, NE R+81
- Mosher, SD R+61
- Winner, SD R+52
- Sparks, NE R+78
- Wewela, SD R+63
- Carter, SD R+56
- Dallas, SD R+67
- Gregory, SD R+64
Cities with Similar Populations
- Imogene, MN R+55
- Tillman, IN R+55
- Club Springs, TN R+64
- Shawneetown, MO R+73
- Cowden, OK R+76
- Seguin, KS R+86
- Fosters Falls, VA R+72
- Inland, NE R+65
- Nassau, MN R+56
- Aycock, LA R+39
All Local Stats
Home Services
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.