Clarendon Hills leans slightly Democratic by roughly 14 points: about 57% of voters vote Democratic and 43% Republican.
About 86% of adults in Clarendon Hills typically vote, above the U.S. average of about 62%. Among adults in Clarendon Hills, ~49% vote Democratic, ~37% Republican, and ~14% don't vote. The map below shows estimated turnout by block group.
How Clarendon Hills compares
Among cities within 25 miles, Clarendon Hills leans more Democratic than 90 of 173 neighbors.
Politically, Clarendon Hills sits close to the rest of Illinois.
Why Clarendon Hills 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 Clarendon Hills, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in Clarendon Hills live in densely developed areas, about 64 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Clarendon Hills sits in the top quarter (about 70%, in the top fraction of cities).
Population density and Democratic lean
Places with high population density tend to lean Democratic; Clarendon Hills, IL sits in the top tenth nationally on this measure.
Why turnout in Clarendon Hills looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Clarendon Hills 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 75%, about 15 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 96% of adults in Clarendon Hills have completed high school, above 87% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Westmont, IL D+16
- Hinsdale, IL D+12
- Willowbrook, IL D+5
- Oak Brook, IL Even
- Downers Grove, IL D+17
- Western Springs, IL D+21
- Darien, IL D+3
- Indian Head Park, IL D+13
- Burr Ridge, IL R+3
- Oakbrook Terrace, IL D+15
Cities with Similar Populations
- South Apopka, FL D+36
- Sykesville, MD R+10
- Chestertown, MD D+8
- Box Elder, SD R+59
- Pecos, TX R+27
- Social Circle, GA R+40
- Barnesville, GA R+20
- Leesville, SC R+61
- Graham, TX R+62
- Cedar Hills, UT R+43
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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.