Green Castle leans heavily Republican by roughly 40 points: about 30% of voters vote Democratic and 70% Republican.
About 83% of adults in Green Castle typically vote, above the U.S. average of about 62%. Among adults in Green Castle, ~25% vote Democratic, ~58% Republican, and ~17% don't vote. The map below shows estimated turnout by block group.
How Green Castle compares
Among cities within 25 miles, Green Castle leans more Republican than 38 of 55 neighbors.
Green Castle runs about 27 points more Republican than Iowa as a whole.
Politics vary noticeably by neighborhood within Green Castle. The northeast side is the most Republican-leaning (R+45) and the south side is the least Republican-leaning (R+27), a spread of about 18 points.
Why Green Castle leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Green Castle. The lean here lands roughly where demographic data alone would predict.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Green Castle, 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 Green Castle looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Green Castle 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 69%, about 9 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Green Castle have completed high school, above 88% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Colfax, IA R+31
- Valeria, IA R+42
- Goddard, IA R+45
- Mitchellville, IA R+22
- Mingo, IA R+43
- Santiago, IA R+27
- Prairie City, IA R+34
- Ira, IA R+45
- Lambs Grove, IA R+37
- Bondurant, IA R+18
Cities with Similar Populations
- Yellow Rock, KY R+66
- Youngs, MS R+42
- Ridgeview, IN R+45
- Tippecanoe, PA R+48
- Cascade-Chipita Park, CO D+3
- Monticello, NM R+38
- Normanda, IN R+57
- Payne, MN R+11
- Bogota, TN R+76
- Wiborg, KY R+76
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.