61115 leans slightly Republican by roughly 14 points: about 43% of voters vote Democratic and 57% Republican.
About 77% of adults in 61115 typically vote, above the U.S. average of about 62%. Among adults in 61115, ~33% vote Democratic, ~44% Republican, and ~23% don't vote. The map below shows estimated turnout by block group.
How 61115 compares
Among zip codes within 15 miles, 61115 leans more Republican than 12 of 21 neighbors.
61115 runs about 25 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while 61115 is one of the few Republican-leaning pockets.
Why 61115 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 61115, not a ranked or complete list of what matters most.
61115 votes Republican even though it is densely developed (about 87%, far above the Illinois average of 33%). State and regional patterns outweigh the Democratic lean that density usually predicts here. 61115 runs against the grain of Illinois, a Republican-leaning pocket in a Democratic-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 61115, IL sits in the top quarter nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in 61115 looks the way it does
Turnout in 61115 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 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.