Hamilton County leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 75% of adults in Hamilton County typically vote, above the U.S. average of about 62%. Among adults in Hamilton County, ~45% vote Democratic, ~30% Republican, and ~25% don't vote. The map below shows estimated turnout by block group.
How Hamilton County compares
Among counties within 50 miles, Hamilton County is the most Democratic-leaning.
Hamilton County runs about 32 points more Democratic than Ohio as a whole. Ohio leans Republican overall, while Hamilton County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Hamilton County. The south side is the most Democratic-leaning (D+62) and the northwest side is the least Democratic-leaning (Even), a spread of about 61 points.
Why Hamilton 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 Hamilton County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 88% of residents in Hamilton County live in densely developed areas, about 52 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Hamilton County sits in the top quarter (about 41%, above 92% of counties). A high never-married share predicts Democratic voting, and about 39% of adults in Hamilton County have never been married, above 92% of counties.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Hamilton County, OH sits in the top tenth nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Hamilton County looks the way it does
Turnout in Hamilton 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
- Campbell County, KY R+16
- Kenton County, KY R+14
- Butler County, OH R+20
- Boone County, KY R+28
- Clermont County, OH R+37
- Warren County, OH R+30
- Dearborn County, IN R+53
- Ohio County, IN R+58
- Pendleton County, KY R+62
- Franklin County, IN R+63
Counties with Similar Populations
- Snohomish County, WA D+10
- Fort Bend County, TX D+6
- Ventura County, CA D+16
- Multnomah County, OR D+52
- Essex County, MA D+18
- Baltimore County, MD D+28
- Montgomery County, PA D+21
- Worcester County, MA D+12
- Middlesex County, NJ D+11
- Suffolk County, MA D+53
All Local Stats
Home Services
Sources and methodology
Precinct-level voting records used to fit the model come from Ohio 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.