Clark County is a Republican stronghold. About 24% of voters here vote Democratic and 76% Republican.
About 84% of adults in Clark County typically vote, above the U.S. average of about 62%. Among adults in Clark County, ~20% vote Democratic, ~64% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How Clark County compares
Among counties within 50 miles, Clark County leans more Republican than 11 of 17 neighbors.
Clark County runs about 64 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Clark County is one of the few Republican-leaning pockets.
Politics vary noticeably by city within Clark County. The south side is the most Republican-leaning (R+60) and the northeast side is the least Republican-leaning (R+47), a spread of about 13 points.
Why Clark 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 Clark County, not a ranked or complete list of what matters most.
Car-dependent areas vote Republican. About 84% of residents in Clark County drive to work alone, about 10 points above the U.S. average of 74%. Clark County runs against the grain of Illinois, a Republican-leaning pocket in a Democratic-leaning state.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Clark 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 Clark County looks the way it does
Homeowners vote more often than renters. About 81% of households in Clark 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
- Edgar County, IL R+50
- Vigo County, IN R+12
- Crawford County, IL R+50
- Cumberland County, IL R+60
- Coles County, IL R+26
- Sullivan County, IN R+49
- Jasper County, IL R+61
- Vermillion County, IN R+50
- Clay County, IN R+52
- Douglas County, IL R+48
Counties with Similar Populations
- Barbour County, WV R+60
- Vermillion County, IN R+50
- Moniteau County, MO R+60
- Brown County, IN R+43
- Floyd County, VA R+47
- Williamsburg City, VA D+43
- Redwood County, MN R+47
- De Witt County, IL R+43
- Washington County, AL R+46
- Tipton County, IN R+52
All Local Stats
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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.