Shiawassee County leans Republican by roughly 28 points: about 36% of voters vote Democratic and 64% Republican.
About 85% of adults in Shiawassee County typically vote, above the U.S. average of about 62%. Among adults in Shiawassee County, ~31% vote Democratic, ~54% Republican, and ~15% don't vote. The map below shows estimated turnout by block group.
How Shiawassee County compares
Among counties within 50 miles, Shiawassee County leans more Republican than 9 of 13 neighbors.
Shiawassee County runs about 26 points more Republican than Michigan as a whole.
Politics vary noticeably by city within Shiawassee County. The southeast side is the most Republican-leaning (R+38) and the north side is the least Republican-leaning (R+18), a spread of about 20 points.
Why Shiawassee County leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in Shiawassee County. The lean here lands roughly where demographic data alone would predict.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; Shiawassee County, MI sits in the top tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in Shiawassee County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Shiawassee 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 67%, about 7 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Clinton County, MI R+12
- Genesee County, MI D+8
- Ingham County, MI D+31
- Livingston County, MI R+23
- Saginaw County, MI D+2
- Eaton County, MI R+8
- Gratiot County, MI R+28
- Lapeer County, MI R+38
- Ionia County, MI R+30
- Bay County, MI R+18
Counties with Similar Populations
- Allegany County, MD R+33
- Lake County, CA R+4
- Madison County, NY R+13
- McCracken County, KY R+30
- Catoosa County, GA R+54
- Otero County, NM R+19
- Carteret County, NC R+35
- Walker County, GA R+61
- Franklin County, NC R+18
- Oldham County, KY R+23
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.