62903 leans slightly Democratic by roughly 10 points: about 55% of voters vote Democratic and 45% Republican.
About 63% of adults in 62903 typically vote, near the U.S. average of about 62%. Among adults in 62903, ~35% vote Democratic, ~28% Republican, and ~37% don't vote. The map below shows estimated turnout by block group.
How 62903 compares
Among zip codes within 15 miles, 62903 leans more Democratic than 15 of 16 neighbors.
Politically, 62903 sits close to the rest of Illinois.
Politics vary noticeably by block within 62903. The northeast side runs the most Democratic (D+25) and the west side runs the most Republican (R+43), a spread of about 68 points.
Why 62903 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 62903, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 46% of adults in 62903 hold a bachelor's degree, about 17 points above the U.S. average of 28%. A high never-married share predicts Democratic voting, and about 49% of adults in 62903 have never been married, above 95% of zip codes.
Adult arthritis and voter turnout
Places with a low adult-arthritis rate tend to turn out at a higher rate; 62903, IL sits in the bottom quarter nationally on this measure. Arthritis does not drive turnout; it reflects the age and health profile of an area.
Why turnout in 62903 looks the way it does
Turnout in 62903 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.