St. Mary leans heavily Democratic by roughly 36 points: about 68% of voters vote Democratic and 32% Republican.
About 54% of adults in St. Mary typically vote, below the U.S. average of about 62%. Among adults in St. Mary, ~37% vote Democratic, ~17% Republican, and ~46% don't vote. The map below shows estimated turnout by block group.
How St. Mary compares
Among cities within 25 miles, St. Mary leans more Democratic than 1 of 6 neighbors.
St. Mary runs about 56 points more Democratic than Montana as a whole. Montana leans Republican overall, while St. Mary is one of the few Democratic-leaning pockets.
Politics vary noticeably by neighborhood within St. Mary. The south side is the most Democratic-leaning (D+51) and the northeast side is the least Democratic-leaning (D+8), a spread of about 43 points.
Why St. Mary leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for St. Mary, not a ranked or complete list of what matters most.
St. Mary votes against the grain of Montana. Montana leans Republican overall, while St. Mary runs about 56 points more Democratic. A high never-married share predicts Democratic voting, and about 46% of adults in St. Mary have never been married, above 97% of cities.
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; St. Mary, MT sits in the bottom quarter nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in St. Mary looks the way it does
Areas with limited routine healthcare access turn out at lower rates. St. Mary is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. High food insecurity lines up with lower turnout, and about 27% of adults in St. Mary report food insecurity, above 93% of cities. High-crime urban areas turn out at lower rates, and St. Mary sits in the top 15% on a violent-crime measure. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Starr School, MT D+64
- Swiftcurrent, MT D+39
- Babb, MT D+47
- Browning, MT D+63
- East Glacier Park, MT D+54
- Del Bonita, MT D+8
- Heart Butte, MT D+63
- Summit, MT R+18
- Essex, MT R+38
- Cut Bank, MT R+24
Cities with Similar Populations
- North Concord, VT R+37
- Rinconada, NM D+13
- Elizabeth, MS R+17
- Battle Hollow, PA R+62
- Highland Park, VA D+9
- Shannondale, AR D+45
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Sources and methodology
Precinct-level voting records used to fit the model come from Montana 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.