Decatur City leans heavily Republican by roughly 46 points: about 27% of voters vote Democratic and 73% Republican.
About 74% of adults in Decatur City typically vote, above the U.S. average of about 62%. Among adults in Decatur City, ~20% vote Democratic, ~54% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.
How Decatur City compares
Among cities within 25 miles, Decatur City leans more Republican than 4 of 33 neighbors.
Decatur City runs about 32 points more Republican than Iowa as a whole.
Politics vary noticeably by neighborhood within Decatur City. The southeast side is the most Republican-leaning (R+61) and the east side is the least Republican-leaning (R+43), a spread of about 18 points.
Why Decatur City leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Decatur City, not a ranked or complete list of what matters most.
Rural areas with a high white share vote Republican. Decatur City sits in the bottom quarter on density and about 97% of residents are non-Hispanic white, about 6 points above the Iowa average of 91%.
Population density and Republican lean
Places with low population density tend to lean Republican; Decatur City, IA sits in the bottom quarter nationally on this measure.
Why turnout in Decatur City looks the way it does
Turnout in Decatur City sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Decatur, IA R+47
- Leon, IA R+50
- Davis City, IA R+60
- Lamoni, IA R+26
- Van Wert, IA R+58
- Grand River, IA R+46
- Kellerton, IA R+53
- Pleasanton, IA R+61
- Woodland, IA R+60
- High Point, IA R+60
Cities with Similar Populations
- Indian Gap, TX R+76
- Martinsburg, IA R+54
- Botkinburg, AR R+63
- Selz, ND R+60
- Cambra, PA R+41
- Elmdale, NY R+40
- Mount Zion, LA R+67
- Max, MN R+21
- East Thermopolis, WY R+69
- Hootentown, KY R+61
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.