Naperville, IL Political Map | Democrat & Republican Areas in Naperville

By the BestNeighborhood data science team. Last updated May 2026.

Naperville leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.

 

About 78% of adults in Naperville typically vote, above the U.S. average of about 62%. Among adults in Naperville, ~48% vote Democratic, ~30% Republican, and ~22% don't vote. The map below shows estimated turnout by block group.

How Naperville compares

Among cities within 25 miles, Naperville leans more Democratic than 125 of 152 neighbors.

Naperville runs about 10 points more Democratic than Illinois as a whole.

Politics vary noticeably by neighborhood within Naperville. The northwest side is the most Democratic-leaning (D+30) and the south side is the least Democratic-leaning (D+17), a spread of about 14 points.

Why Naperville 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 Naperville, not a ranked or complete list of what matters most.

Areas with high college attainment vote Democratic. About 72% of adults in Naperville hold a bachelor's degree, about 43 points above the U.S. average of 28%. Dense areas vote Democratic, and Naperville sits in the top fifth on density (about 94%, above 97% of cities).

Walkability and Democratic lean

Places with a highly walkable street grid tend to lean Democratic; Naperville, IL sits in the top tenth 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 Naperville looks the way it does

Areas with strong routine healthcare access turn out at higher rates. Naperville 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 74%, about 14 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Naperville have completed high school, above 91% of cities. Learn more about the findings and methodology on the political spectrum map.

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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.