Washtenaw County leans heavily Democratic by roughly 44 points: about 72% of voters vote Democratic and 28% Republican.
About 84% of adults in Washtenaw County typically vote, above the U.S. average of about 62%. Among adults in Washtenaw County, ~60% vote Democratic, ~24% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How Washtenaw County compares
Among counties within 50 miles, Washtenaw County is the most Democratic-leaning.
Washtenaw County runs about 45 points more Democratic than Michigan as a whole. Michigan is roughly evenly split, and Washtenaw County sits clearly on the Democratic side.
Politics vary noticeably by city within Washtenaw County. The north side is the most Democratic-leaning (D+60) and the southwest side is the least Democratic-leaning (D+6), a spread of about 54 points.
Why Washtenaw 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 Washtenaw County, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 59% of adults in Washtenaw County hold a bachelor's degree, about 30 points above the U.S. average of 28%. Dense areas vote Democratic, and Washtenaw County sits in the top fifth on density (about 72%, above 92% of counties). Washtenaw County runs against the grain of Michigan, a Democratic-leaning outlier in a roughly evenly split state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Washtenaw County, MI sits in the top tenth nationally on this measure.
Why turnout in Washtenaw County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Washtenaw 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 72%, about 12 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 96% of adults in Washtenaw County have completed high school, above 97% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Livingston County, MI R+23
- Wayne County, MI D+33
- Monroe County, MI R+27
- Lenawee County, MI R+27
- Oakland County, MI D+14
- Jackson County, MI R+14
- Lucas County, OH D+17
- Macomb County, MI R+10
- Ingham County, MI D+31
- Fulton County, OH R+45
Counties with Similar Populations
- Brazoria County, TX R+17
- Bell County, TX R+3
- Lehigh County, PA D+6
- Stark County, OH R+18
- Collier County, FL R+20
- Marion County, FL R+28
- Hamilton County, TN R+10
- Chesterfield County, VA D+12
- Anoka County, MN Even
- Davis County, UT R+24
Sources and methodology
Precinct-level voting records used to fit the model come from Michigan Department 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.