Kane County leans slightly Democratic by roughly 14 points: about 57% of voters vote Democratic and 43% Republican.
About 69% of adults in Kane County typically vote, above the U.S. average of about 62%. Among adults in Kane County, ~39% vote Democratic, ~30% Republican, and ~31% don't vote. The map below shows estimated turnout by block group.
How Kane County compares
Among counties within 50 miles, Kane County leans more Democratic than 10 of 13 neighbors.
Politically, Kane County sits close to the rest of Illinois.
Politics vary noticeably by city within Kane County. The southeast side runs the most Democratic (D+30) and the west side runs the most Republican (R+10), a spread of about 39 points.
Why Kane County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Kane County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 79% of residents in Kane County live in densely developed areas, about 43 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Kane County sits in the top quarter (about 37%, above 89% of counties). A high never-married share predicts Democratic voting, and about 33% of adults in Kane County have never been married, above 76% of counties.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Kane County, IL sits in the top tenth nationally on this measure.
Why turnout in Kane County looks the way it does
Turnout in Kane County 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 Counties
- DuPage County, IL D+14
- Kendall County, IL Even
- DeKalb County, IL D+3
- McHenry County, IL R+5
- Will County, IL D+6
- Cook County, IL D+42
- Lake County, IL D+22
- Boone County, IL R+15
- Grundy County, IL R+26
- Winnebago County, IL D+7
Counties with Similar Populations
- Adams County, CO D+11
- Camden County, NJ D+30
- Morris County, NJ Even
- Sedgwick County, KS R+7
- Passaic County, NJ D+4
- Greenville County, SC R+14
- Clark County, WA D+7
- Plymouth County, MA D+11
- Lake County, IN D+14
- Chester County, PA D+14
All Local Stats
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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.