St. Mary Parish leans Republican by roughly 22 points: about 39% of voters vote Democratic and 61% Republican.
About 63% of adults in St. Mary Parish typically vote, near the U.S. average of about 62%. Among adults in St. Mary Parish, ~25% vote Democratic, ~38% Republican, and ~37% don't vote. The map below shows estimated turnout by block group.
How St. Mary Parish compares
Among counties within 50 miles, St. Mary Parish leans more Republican than 3 of 9 neighbors.
Politically, St. Mary Parish sits close to the rest of Louisiana.
Politics vary noticeably by city within St. Mary Parish. The northwest side runs the most Democratic (D+9) and the east side runs the most Republican (R+48), a spread of about 57 points.
Why St. Mary Parish 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 St. Mary Parish, not a ranked or complete list of what matters most.
Areas with low college attainment vote Republican. About 13% of adults in St. Mary Parish hold a bachelor's degree, about 6 points below the Louisiana average of 19%. Car-dependent areas vote Republican, and about 84% of residents in St. Mary Parish drive to work alone, above 92% of counties.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; St. Mary Parish, LA 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 St. Mary Parish looks the way it does
Turnout in St. Mary Parish 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
- Assumption Parish, LA R+30
- Iberia Parish, LA R+24
- Iberville Parish, LA R+6
- Terrebonne Parish, LA R+42
- St. James Parish, LA D+3
- Lafourche Parish, LA R+55
- Ascension Parish, LA R+32
- St. Martin Parish, LA R+35
- West Baton Rouge Parish, LA R+9
- East Baton Rouge Parish, LA D+23
Counties with Similar Populations
- Dale County, AL R+43
- Douglas County, NV R+32
- Henry County, IL R+24
- Montgomery County, NY R+24
- Logan County, OK R+45
- Laurens County, GA R+19
- Winona County, MN R+8
- Burnet County, TX R+56
- Wilson County, TX R+50
- Atascosa County, TX R+37
Sources and methodology
Precinct-level voting records used to fit the model come from Louisiana 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.