Mercer County is a Republican stronghold. About 15% of voters here vote Democratic and 85% Republican.
About 74% of adults in Mercer County typically vote, above the U.S. average of about 62%. Among adults in Mercer County, ~11% vote Democratic, ~63% Republican, and ~26% don't vote. The map below shows estimated turnout by block group.
How Mercer County compares
Among counties within 50 miles, Mercer County is the most Republican-leaning.
Mercer County runs about 51 points more Republican than Missouri as a whole.
Why Mercer 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 Mercer County, not a ranked or complete list of what matters most.
Areas with a high white share and below-average college attainment vote Republican. In Mercer County, about 92% of residents are non-Hispanic white, about 19 points above the U.S. average of 72%; about 18% of adults hold a bachelor's degree, about 11 points below the U.S. average of 28%. Rural areas vote Republican, and Mercer County sits in the bottom quarter on density (about 5%, below 95% of counties).
Walkability and Republican lean
Places with a low walkability score tend to lean Republican; Mercer County, MO sits in the bottom quarter nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Mercer County looks the way it does
Homeowners vote more often than renters. About 82% of households in Mercer County own their home, about 7 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Grundy County, MO R+57
- Harrison County, MO R+64
- Decatur County, IA R+44
- Wayne County, IA R+56
- Sullivan County, MO R+56
- Putnam County, MO R+68
- Daviess County, MO R+63
- Ringgold County, IA R+50
- Livingston County, MO R+52
- Appanoose County, IA R+43
Counties with Similar Populations
- Sheridan County, MT R+58
- Lewis County, ID R+60
- Hardeman County, TX R+60
- Smith County, KS R+72
- Baca County, CO R+69
- Osborne County, KS R+74
- Costilla County, CO D+19
- Catron County, NM R+36
- Baylor County, TX R+66
- Hanson County, SD R+72
All Local Stats
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Sources and methodology
Precinct-level voting records used to fit the model come from Missouri 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.