Shelby County is a Republican stronghold. About 21% of voters here vote Democratic and 79% Republican.
About 82% of adults in Shelby County typically vote, above the U.S. average of about 62%. Among adults in Shelby County, ~17% vote Democratic, ~65% Republican, and ~18% don't vote. The map below shows estimated turnout by block group.
How Shelby County compares
Among counties within 50 miles, Shelby County leans more Republican than 9 of 12 neighbors.
Shelby County runs about 69 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while Shelby County is one of the few Republican-leaning pockets.
Why Shelby 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 Shelby County, not a ranked or complete list of what matters most.
Areas with a high white share and below-average college attainment vote Republican. In Shelby County, about 96% of residents are non-Hispanic white, about 24 points above the U.S. average of 72%; about 18% of adults hold a bachelor's degree, about 8 points below the Illinois average of 27%. Car-dependent areas vote Republican, and about 84% of residents in Shelby County drive to work alone, above 91% of counties. Shelby County runs against the grain of Illinois, a Republican-leaning pocket in a Democratic-leaning state.
High-school completion and voter turnout
Places with high-school-completion-heavy adults tend to turn out at a higher rate; Shelby County, IL sits in the top tenth nationally on this measure.
Why turnout in Shelby County looks the way it does
Areas with high high-school completion turn out at higher rates. About 95% of adults in Shelby County have completed high school, about 5 points above the U.S. average of 90%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Moultrie County, IL R+54
- Effingham County, IL R+56
- Christian County, IL R+45
- Cumberland County, IL R+60
- Coles County, IL R+26
- Fayette County, IL R+59
- Macon County, IL R+8
- Douglas County, IL R+48
- Montgomery County, IL R+44
- Piatt County, IL R+35
Counties with Similar Populations
- Morgan County, MO R+63
- Fairfield County, SC D+13
- Morgan County, TN R+70
- Perry County, IL R+49
- Assumption Parish, LA R+30
- Union Parish, LA R+49
- Dodge County, MN R+31
- Washington County, NE R+42
- Bandera County, TX R+59
- Logan County, AR R+63
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.