57004 leans heavily Republican by roughly 50 points: about 25% of voters vote Democratic and 75% Republican.
About 65% of adults in 57004 typically vote, near the U.S. average of about 62%. Among adults in 57004, ~16% vote Democratic, ~48% Republican, and ~36% don't vote. The map below shows estimated turnout by block group.
How 57004 compares
Among zip codes within 15 miles, 57004 leans more Republican than 1 of 3 neighbors.
57004 runs about 20 points more Republican than South Dakota as a whole.
Why 57004 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 57004. The lean here lands roughly where demographic data alone would predict.
Population density and Republican lean
Places with low population density tend to lean Republican; 57004, SD sits in the bottom quarter nationally on this measure.
Why turnout in 57004 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 57004 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 71%, about 11 points above the U.S. average of 60%. 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.