57766 is a Republican stronghold. About 14% of voters here vote Democratic and 86% Republican.
About 65% of adults in 57766 typically vote, near the U.S. average of about 62%. Among adults in 57766, ~9% vote Democratic, ~56% Republican, and ~35% don't vote. The map below shows estimated turnout by block group.
How 57766 compares
57766 sits in a sparsely populated area with few comparable zip codes nearby.
57766 runs about 42 points more Republican than South Dakota as a whole.
Why 57766 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 57766. 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; 57766, SD sits in the bottom tenth nationally on this measure.
Why turnout in 57766 looks the way it does
Areas with high high-school completion turn out at higher rates. About 98% of adults in 57766 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 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.