Clinton County leans Republican by roughly 20 points: about 40% of voters vote Democratic and 60% Republican.
About 80% of adults in Clinton County typically vote, above the U.S. average of about 62%. Among adults in Clinton County, ~32% vote Democratic, ~48% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How Clinton County compares
Among counties within 50 miles, Clinton County leans more Republican than 7 of 14 neighbors.
Clinton County runs about 8 points more Republican than Iowa as a whole.
Politics vary noticeably by city within Clinton County. The north side is the most Republican-leaning (R+47) and the east side is the least Republican-leaning (R+5), a spread of about 42 points.
Why Clinton 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 Clinton County, not a ranked or complete list of what matters most.
Car-dependent areas vote Republican. About 82% of residents in Clinton County drive to work alone, about 8 points above the U.S. average of 74%.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; Clinton County, IA sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Clinton County looks the way it does
Turnout in Clinton County 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 Counties
- Scott County, IA D+5
- Jackson County, IA R+35
- Carroll County, IL R+34
- Rock Island County, IL D+12
- Whiteside County, IL R+20
- Henry County, IL R+24
- Jo Daviess County, IL R+18
- Cedar County, IA R+34
- Muscatine County, IA R+16
- Mercer County, IL R+33
Counties with Similar Populations
- Allegany County, NY R+39
- Stevens County, WA R+37
- Jackson County, IN R+51
- Auglaize County, OH R+59
- Charlottesville City, VA D+60
- Chambers County, TX R+58
- Monroe County, WI R+28
- Monroe County, TN R+67
- Beltrami County, MN R+4
- Barron County, WI R+28
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.