Miami County leans heavily Republican by roughly 42 points: about 29% of voters vote Democratic and 71% Republican.
About 79% of adults in Miami County typically vote, above the U.S. average of about 62%. Among adults in Miami County, ~23% vote Democratic, ~56% Republican, and ~21% don't vote. The map below shows estimated turnout by block group.
How Miami County compares
Among counties within 50 miles, Miami County leans more Republican than 9 of 19 neighbors.
Miami County runs about 31 points more Republican than Ohio as a whole.
Politics vary noticeably by city within Miami County. The northeast side is the most Republican-leaning (R+60) and the southeast side is the least Republican-leaning (R+37), a spread of about 23 points.
Why Miami 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 Miami County, not a ranked or complete list of what matters most.
Miami County votes Republican even though it is densely developed (about 49%, modestly above the Ohio average of 34%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
Food insecurity and voter turnout
Places with low food insecurity tend to turn out at a higher rate; Miami County, OH sits in the bottom quarter nationally on this measure. Food insecurity does not directly drive turnout; it reflects economic hardship, which lines up with lower voting.
Why turnout in Miami County looks the way it does
Turnout in Miami 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
- Shelby County, OH R+58
- Montgomery County, OH D+6
- Darke County, OH R+61
- Clark County, OH R+21
- Greene County, OH R+17
- Champaign County, OH R+51
- Preble County, OH R+58
- Logan County, OH R+51
- Auglaize County, OH R+59
- Mercer County, OH R+65
Counties with Similar Populations
- Bartow County, GA R+46
- Bradley County, TN R+48
- St. Lawrence County, NY R+18
- Madison County, MS R+5
- Eaton County, MI R+8
- Pennington County, SD R+28
- Terrebonne Parish, LA R+42
- Warren County, NJ R+16
- LaSalle County, IL R+21
- Cass County, MO R+32
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.