57104 leans slightly Democratic by roughly 8 points: about 54% of voters vote Democratic and 46% Republican.
About 51% of adults in 57104 typically vote, below the U.S. average of about 62%. Among adults in 57104, ~28% vote Democratic, ~23% Republican, and ~49% don't vote. The map below shows estimated turnout by block group.
How 57104 compares
Among zip codes within 15 miles, 57104 leans more Democratic than 14 of 16 neighbors.
57104 runs about 37 points more Democratic than South Dakota as a whole. South Dakota leans Republican overall, while 57104 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 57104. The south side runs the most Democratic (D+25) and the northeast side runs the most Republican (R+23), a spread of about 47 points.
Why 57104 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 57104, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 93% of residents in 57104 live in densely developed areas, about 57 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 44% of adults in 57104 have never been married, above 91% of zip codes. 57104 runs against the grain of South Dakota, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 57104, SD sits in the top tenth nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in 57104 looks the way it does
Renters vote less often than owners. About 48% of households in 57104 rent, about 23 points above the U.S. average of 25%. 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.