Warren County leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 89% of adults in Warren County typically vote, above the U.S. average of about 62%. Among adults in Warren County, ~34% vote Democratic, ~55% Republican, and ~11% don't vote. The map below shows estimated turnout by block group.
How Warren County compares
Among counties within 50 miles, Warren County leans more Republican than 3 of 16 neighbors.
Warren County runs about 11 points more Republican than Iowa as a whole.
Politics vary noticeably by city within Warren County. The southeast side is the most Republican-leaning (R+45) and the northwest side is the least Republican-leaning (R+19), a spread of about 27 points.
Why Warren County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Warren County, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 70% of households in Warren County are family households, above 79% of counties.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Warren County, IA sits in the top tenth 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 Warren County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Warren County 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 70%, about 10 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 83% of households in Warren County own their home, above 90% of counties. High high-school completion lines up with higher turnout, and about 97% of adults in Warren County have completed high school, above 98% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Polk County, IA D+12
- Madison County, IA R+41
- Dallas County, IA R+7
- Clarke County, IA R+41
- Marion County, IA R+34
- Lucas County, IA R+44
- Jasper County, IA R+28
- Story County, IA D+14
- Union County, IA R+33
- Boone County, IA R+24
Counties with Similar Populations
- Calumet County, WI R+23
- Ashland County, OH R+50
- Washington County, OK R+40
- Worcester County, MD R+12
- Grundy County, IL R+26
- St. Charles Parish, LA R+25
- Culpeper County, VA R+23
- Jackson County, AL R+71
- Columbia County, OR R+18
- Rusk County, TX R+53
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.