63140 is a Democratic stronghold. About 89% of voters here vote Democratic and 11% Republican.
About 51% of adults in 63140 typically vote, below the U.S. average of about 62%. Among adults in 63140, ~46% vote Democratic, ~6% Republican, and ~48% don't vote. The map below shows estimated turnout by block group.
How 63140 compares
Among zip codes within 15 miles, 63140 leans more Democratic than 50 of 66 neighbors.
63140 runs about 96 points more Democratic than Missouri as a whole. Missouri leans Republican overall, while 63140 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 63140. The north side is the most Democratic-leaning (D+85) and the southeast side is the least Democratic-leaning (D+73), a spread of about 12 points.
Why 63140 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 63140, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 63140 live in densely developed areas, about 64 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 45% of adults in 63140 have never been married, above 92% of zip codes. 63140 runs against the grain of Missouri, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 63140, MO sits in the top tenth 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 63140 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 63140 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 39%, about 19 points below the Missouri average of 57%. Renters vote less often than owners, and about 56% of households in 63140 rent, about 31 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 40% of adults in 63140 report food insecurity, above 98% of zip codes. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
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.