St. Charles leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 83% of adults in St. Charles typically vote, above the U.S. average of about 62%. Among adults in St. Charles, ~44% vote Democratic, ~39% Republican, and ~17% don't vote. The map below shows estimated turnout by block group.
How St. Charles compares
Among cities within 25 miles, St. Charles leans more Democratic than 64 of 133 neighbors.
St. Charles runs about 5 points more Republican than Illinois as a whole.
Politics vary noticeably by neighborhood within St. Charles. The south side runs the most Democratic (D+21) and the northwest side runs the most Republican (R+8), a spread of about 29 points.
Why St. Charles leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for St. Charles, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 85% of residents in St. Charles live in densely developed areas, about 49 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and St. Charles sits in the top quarter (about 52%, above 94% of cities).
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; St. Charles, IL sits in the top quarter nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in St. Charles looks the way it does
Areas with strong routine healthcare access turn out at higher rates. St. Charles is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 72%, about 12 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Geneva, IL D+12
- Wayne, IL R+7
- South Elgin, IL D+4
- Campton Hills, IL R+14
- Lafox, IL R+6
- Wayne Center, IL D+10
- Batavia, IL D+15
- Mooseheart, IL D+7
- West Chicago, IL D+9
- Elburn, IL R+14
Cities with Similar Populations
- The Acreage, FL R+23
- Ellenwood, GA D+76
- South El Monte, CA D+28
- Beverly, MA D+29
- Kent, OH D+23
- Dunedin, FL R+10
- Fair Oaks, CA D+6
- Hudson, FL R+37
- Elkton, MD R+17
- Lumberton, NC R+11
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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.