Randolph County leans heavily Republican by roughly 46 points: about 27% of voters vote Democratic and 73% Republican.
About 70% of adults in Randolph County typically vote, above the U.S. average of about 62%. Among adults in Randolph County, ~19% vote Democratic, ~51% Republican, and ~30% don't vote. The map below shows estimated turnout by block group.
How Randolph County compares
Among counties within 50 miles, Randolph County leans more Republican than 5 of 13 neighbors.
Randolph County runs about 56 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Randolph County is one of the few Republican-leaning pockets.
Politics vary noticeably by city within Randolph County. The west side is the most Republican-leaning (R+56) and the east side is the least Republican-leaning (R+33), a spread of about 22 points.
Why Randolph 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 Randolph County, not a ranked or complete list of what matters most.
Randolph County votes against the grain of Illinois. Illinois leans Democratic overall, while Randolph County runs about 56 points more Republican. Car-dependent areas vote Republican, and about 83% of residents in Randolph County drive to work alone, above 86% of counties. Low college attainment predicts Republican voting, and Randolph County sits in the bottom quarter (about 16%, below 84% of counties).
Renting and voter turnout
Places with homeowner-heavy households tend to turn out at a higher rate; Randolph County, IL sits below the national average on this measure.
Why turnout in Randolph County looks the way it does
Turnout in Randolph 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
- Ste. Genevieve County, MO R+55
- Perry County, MO R+62
- Perry County, IL R+49
- Monroe County, IL R+39
- Washington County, IL R+53
- St. Clair County, IL D+13
- Jackson County, IL D+7
- St. Francois County, MO R+48
- Clinton County, IL R+47
- Jefferson County, MO R+39
Counties with Similar Populations
- Austin County, TX R+54
- Wayne County, GA R+52
- Knox County, KY R+65
- Madison County, GA R+55
- McPherson County, KS R+44
- Caledonia County, VT R+9
- Iberville Parish, LA R+6
- Cass County, MN R+30
- Door County, WI R+3
- Ottawa County, OK R+53
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.