57108 leans Republican by roughly 18 points: about 41% of voters vote Democratic and 59% Republican.
About 88% of adults in 57108 typically vote, above the U.S. average of about 62%. Among adults in 57108, ~36% vote Democratic, ~52% Republican, and ~12% don't vote. The map below shows estimated turnout by block group.
How 57108 compares
Among zip codes within 15 miles, 57108 leans more Republican than 6 of 19 neighbors.
57108 runs about 12 points more Democratic than South Dakota as a whole.
Politics vary noticeably by block within 57108. The southeast side is the most Republican-leaning (R+36) and the northeast side is the least Republican-leaning (R+9), a spread of about 27 points.
Why 57108 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 57108, not a ranked or complete list of what matters most.
57108 votes Republican even though it is densely developed (about 76%, far above the South Dakota average of 9%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
High-school completion, uninsured rate, and voter turnout
Places that combine high-school-completion-heavy adults and a low uninsured rate tend to turn out at a higher rate, as 57108, SD does.
Why turnout in 57108 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 57108 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 75%, about 15 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in 57108 have completed high school, above 91% 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.