Henry County leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 80% of adults in Henry County typically vote, above the U.S. average of about 62%. Among adults in Henry County, ~30% vote Democratic, ~50% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How Henry County compares
Among counties within 50 miles, Henry County leans more Republican than 9 of 14 neighbors.
Henry County runs about 35 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Henry County is one of the few Republican-leaning pockets.
Politics vary noticeably by city within Henry County. The northeast side is the most Republican-leaning (R+44) and the southeast side is the least Republican-leaning (R+13), a spread of about 30 points.
Why Henry 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 Henry County, not a ranked or complete list of what matters most.
Henry County votes against the grain of Illinois. Illinois leans Democratic overall, while Henry County runs about 35 points more Republican.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Henry County, IL sits above the national average 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 Henry County looks the way it does
Homeowners vote more often than renters. About 81% of households in Henry County own their home, about 6 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Rock Island County, IL D+12
- Stark County, IL R+47
- Scott County, IA D+5
- Mercer County, IL R+33
- Knox County, IL R+9
- Whiteside County, IL R+20
- Clinton County, IA R+21
- Bureau County, IL R+27
- Warren County, IL R+22
- Putnam County, IL R+28
Counties with Similar Populations
- Dale County, AL R+43
- St. Mary Parish, LA R+23
- Burnet County, TX R+56
- Douglas County, NV R+32
- Montgomery County, NY R+24
- Logan County, OK R+45
- Laurens County, GA R+19
- Atascosa County, TX R+37
- Fremont County, CO R+25
- Henry County, IN R+47
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Sources and methodology
Precinct-level voting records used to fit the model come from Illinois State Board of 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.