Cook County leans heavily Democratic by roughly 32 points: about 66% of voters vote Democratic and 34% Republican.
About 80% of adults in Cook County typically vote, above the U.S. average of about 62%. Among adults in Cook County, ~53% vote Democratic, ~27% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How Cook County compares
Cook County runs about 28 points more Democratic than Minnesota as a whole.
Politics vary noticeably by city within Cook County. The west side is the most Democratic-leaning (D+37) and the southeast side is the least Democratic-leaning (D+27), a spread of about 10 points.
Why Cook 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 Cook County, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 47% of adults in Cook County hold a bachelor's degree, about 19 points above the U.S. average of 28%.
High-school completion, developed land, and voter turnout
Places that combine high-school-completion-heavy adults and a rural land-use pattern tend to turn out at a higher rate, as Cook County, MN does.
Why turnout in Cook County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Cook County 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 70%, about 10 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Cook County have completed high school, above 98% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Lake County, MN R+5
- Ontonagon County, MI R+26
- Bayfield County, WI D+6
- Ashland County, WI Even
- Gogebic County, MI R+14
- Houghton County, MI D+5
- Iron County, WI R+27
- Keweenaw County, MI Even
- St. Louis County, MN D+12
- Douglas County, WI Even
Counties with Similar Populations
- Lynn County, TX R+61
- Dixon County, NE R+56
- Cameron Parish, LA R+86
- Tripp County, SD R+58
- Calhoun County, GA D+13
- Putnam County, IL R+28
- Lincoln County, MN R+49
- Fillmore County, NE R+57
- Bent County, CO R+29
- Gray County, KS R+73
Sources and methodology
Precinct-level voting records used to fit the model come from Minnesota Secretary of State, 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.