61731 is a Republican stronghold. About 23% of voters here vote Democratic and 77% Republican.
About 94% of adults in 61731 typically vote, above the U.S. average of about 62%. Among adults in 61731, ~22% vote Democratic, ~73% Republican, and ~5% don't vote. The map below shows estimated turnout by block group.
How 61731 compares
Among zip codes within 15 miles, 61731 leans more Republican than 8 of 13 neighbors.
61731 runs about 64 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while 61731 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 61731. The northeast side is the most Republican-leaning (R+63) and the south side is the least Republican-leaning (R+50), a spread of about 14 points.
Why 61731 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 61731, not a ranked or complete list of what matters most.
61731 votes against the grain of Illinois. Illinois leans Democratic overall, while 61731 runs about 64 points more Republican. Rural areas vote Republican, and 61731 sits in the bottom quarter on density (about 6%, below 76% of zip codes).
Population density and Republican lean
Places with low population density tend to lean Republican; 61731, IL sits in the bottom tenth nationally on this measure.
Why turnout in 61731 looks the way it does
Areas with high high-school completion turn out at higher rates. About 98% of adults in 61731 have completed high school, about 6 points above the Illinois average of 92%. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
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.