Miami County leans heavily Republican by roughly 44 points: about 28% of voters vote Democratic and 72% Republican.
About 62% of adults in Miami County typically vote, near the U.S. average of about 62%. Among adults in Miami County, ~17% vote Democratic, ~45% Republican, and ~38% 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 7 of 19 neighbors.
Miami County runs about 26 points more Republican than Indiana as a whole.
Politics vary noticeably by city within Miami County. The northeast side is the most Republican-leaning (R+61) and the southwest side is the least Republican-leaning (R+33), a spread of about 28 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.
Car-dependent areas vote Republican. About 83% of residents in Miami County drive to work alone, about 9 points above the U.S. average of 74%. Low college attainment predicts Republican voting, and Miami County sits in the bottom quarter (about 15%, below 85% of counties).
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Miami County, IN sits in the top quarter 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 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
- Cass County, IN R+38
- Wabash County, IN R+48
- Howard County, IN R+30
- Fulton County, IN R+51
- Grant County, IN R+34
- Tipton County, IN R+52
- Carroll County, IN R+53
- Huntington County, IN R+45
- Clinton County, IN R+45
- White County, IN R+43
Counties with Similar Populations
- Greenup County, KY R+52
- Greene County, PA R+43
- Floyd County, KY R+61
- Cocke County, TN R+65
- Laclede County, MO R+61
- Hill County, TX R+58
- Sioux County, IA R+55
- Scotts Bluff County, NE R+42
- Livingston County, IL R+38
- Adams County, IN R+60
Sources and methodology
Precinct-level voting records used to fit the model come from Indiana 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.