62305 leans heavily Republican by roughly 48 points: about 26% of voters vote Democratic and 74% Republican.
About 85% of adults in 62305 typically vote, above the U.S. average of about 62%. Among adults in 62305, ~22% vote Democratic, ~63% Republican, and ~15% don't vote. The map below shows estimated turnout by block group.
How 62305 compares
Among zip codes within 15 miles, 62305 leans more Republican than 1 of 12 neighbors.
62305 runs about 58 points more Republican than Illinois as a whole. Illinois leans Democratic overall, while 62305 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 62305. The northeast side is the most Republican-leaning (R+64) and the west side is the least Republican-leaning (R+33), a spread of about 31 points.
Why 62305 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 62305, not a ranked or complete list of what matters most.
62305 votes against the grain of Illinois. Illinois leans Democratic overall, while 62305 runs about 58 points more Republican.
High-school completion, uninsured rate, and voter turnout
Places that combine high-school-completion-heavy adults and a low uninsured rate tend to turn out at a higher rate, as 62305, IL does.
Why turnout in 62305 looks the way it does
Areas with high high-school completion turn out at higher rates. About 96% of adults in 62305 have completed high school, about 7 points above the U.S. average of 90%. 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.