63040 leans slightly Republican by roughly 10 points: about 45% of voters vote Democratic and 55% Republican.
About 88% of adults in 63040 typically vote, above the U.S. average of about 62%. Among adults in 63040, ~40% vote Democratic, ~48% Republican, and ~12% don't vote. The map below shows estimated turnout by block group.
How 63040 compares
Among zip codes within 15 miles, 63040 leans more Republican than 17 of 33 neighbors.
63040 runs about 8 points more Democratic than Missouri as a whole.
Why 63040 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 63040, not a ranked or complete list of what matters most.
63040 votes Republican even though it is densely developed (about 85%, far above the Missouri average of 22%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 76% of households in 63040 are family households, above 82% of zip codes.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 63040, MO sits in the top tenth 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 63040 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 63040 is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 75%, about 15 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 92% of households in 63040 own their home, about 17 points above the U.S. average of 75%. High high-school completion lines up with higher turnout, and about 98% of adults in 63040 have completed high school, above 93% 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.