51556 is a Republican stronghold. About 25% of voters here vote Democratic and 75% Republican.
About 79% of adults in 51556 typically vote, above the U.S. average of about 62%. Among adults in 51556, ~20% vote Democratic, ~59% Republican, and ~21% don't vote. The map below shows estimated turnout by block group.
How 51556 compares
Among zip codes within 15 miles, 51556 leans more Republican than 8 of 10 neighbors.
51556 runs about 37 points more Republican than Iowa as a whole.
Why 51556 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 51556, not a ranked or complete list of what matters most.
Rural areas vote Republican. About 5% of residents in 51556 live in densely developed areas, about 11 points below the Iowa average of 16%. Low college attainment predicts Republican voting, and 51556 sits in the bottom quarter (about 13%, below 89% of zip codes). A high family-household share predicts Republican voting, and about 75% of households in 51556 are family households, above 81% of zip codes.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 51556, IA sits in the top quarter nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in 51556 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 51556 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 68%, about 8 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 Iowa 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.