St. Peters leans slightly Republican by roughly 8 points: about 46% of voters vote Democratic and 54% Republican.
About 78% of adults in St. Peters typically vote, above the U.S. average of about 62%. Among adults in St. Peters, ~36% vote Democratic, ~42% Republican, and ~22% don't vote. The map below shows estimated turnout by block group.
How St. Peters compares
Among cities within 25 miles, St. Peters leans more Republican than 88 of 158 neighbors.
St. Peters runs about 10 points more Democratic than Missouri as a whole.
Politics vary noticeably by neighborhood within St. Peters. The southwest side is the most Republican-leaning (R+17) and the northeast side is the least Republican-leaning (R+5), a spread of about 11 points.
Why St. Peters 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. Peters, not a ranked or complete list of what matters most.
St. Peters votes Republican even though it is densely developed (about 96%, far above the Missouri average of 22%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; St. Peters, MO sits in the top 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. Peters looks the way it does
Areas with high high-school completion turn out at higher rates. About 96% of adults in St. Peters have completed high school, about 6 points above the Missouri average of 89%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Cottleville, MO R+16
- Weldon Spring, MO R+23
- St. Charles, MO R+6
- O'fallon, MO R+16
- Kampville, MO R+43
- Dardenne Prairie, MO R+17
- Weldon Spring Heights, MO R+31
- St. Paul, MO R+32
- Lake St. Louis, MO R+16
Cities with Similar Populations
- Perris, CA D+14
- Oshkosh, WI D+3
- Pleasanton, CA D+32
- Sumter, SC D+6
- Yukon, OK R+34
- Arlington Heights, IL D+19
- San Marcos, TX D+20
- Yuba City, CA R+20
- Warner Robins, GA D+10
- Buford, GA R+3
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.