57003 is a Republican stronghold. About 23% of voters here vote Democratic and 77% Republican.
About 67% of adults in 57003 typically vote, near the U.S. average of about 62%. Among adults in 57003, ~15% vote Democratic, ~52% Republican, and ~33% don't vote. The map below shows estimated turnout by block group.
How 57003 compares
Among zip codes within 15 miles, 57003 is the most Republican-leaning.
57003 runs about 24 points more Republican than South Dakota as a whole.
Why 57003 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 57003, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 83% of households in 57003 are family households, about 17 points above the U.S. average of 67%.
Never-married share, developed land, and voter turnout
Places that combine a low never-married share and a rural land-use pattern tend to turn out at a higher rate, as 57003, SD does.
Why turnout in 57003 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 57003 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 70%, about 10 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 96% of adults in 57003 have completed high school, above 81% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
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.