Marion County leans Democratic by roughly 16 points: about 58% of voters vote Democratic and 42% Republican.
About 68% of adults in Marion County typically vote, above the U.S. average of about 62%. Among adults in Marion County, ~39% vote Democratic, ~29% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How Marion County compares
Among counties within 50 miles, Marion County leans more Democratic than 9 of 10 neighbors.
Marion County runs about 35 points more Democratic than South Carolina as a whole. South Carolina leans Republican overall, while Marion County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Marion County. The southwest side runs the most Democratic (D+40) and the southeast side runs the most Republican (R+4), a spread of about 44 points.
Why Marion 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 Marion County, not a ranked or complete list of what matters most.
Areas with many never-married adults vote Democratic. About 44% of adults in Marion County have never been married, well above similar-sized counties (around 28%). Marion County runs against the grain of South Carolina, a Democratic-leaning pocket in a Republican-leaning state.
Park access and Republican lean
Places with low park coverage tend to lean Republican; Marion County, SC sits in the bottom quarter nationally on this measure. Park access does not change how people vote; it tends to track denser, higher-income areas.
Why turnout in Marion County looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Marion County is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 49%, about 9 points below the South Carolina average of 58%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Dillon County, SC R+5
- Florence County, SC Even
- Horry County, SC R+30
- Columbus County, NC R+27
- Marlboro County, SC D+9
- Robeson County, NC R+13
- Darlington County, SC R+8
- Williamsburg County, SC D+26
- Scotland County, NC D+2
- Georgetown County, SC R+17
Counties with Similar Populations
- Carroll County, VA R+63
- Gallia County, OH R+57
- Morgan County, CO R+37
- Grimes County, TX R+42
- Hancock County, WV R+42
- Orange County, VT Even
- Neshoba County, MS R+31
- Mason County, MI R+20
- Marion County, AL R+79
- Decatur County, GA R+10
Sources and methodology
Precinct-level voting records used to fit the model come from South Carolina State Election Commission, 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.