63034 is a Democratic stronghold. About 82% of voters here vote Democratic and 18% Republican.
About 81% of adults in 63034 typically vote, above the U.S. average of about 62%. Among adults in 63034, ~66% vote Democratic, ~14% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How 63034 compares
Among zip codes within 15 miles, 63034 leans more Democratic than 33 of 55 neighbors.
63034 runs about 82 points more Democratic than Missouri as a whole. Missouri leans Republican overall, while 63034 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 63034. The southeast side is the most Democratic-leaning (D+73) and the northeast side is the least Democratic-leaning (D+48), a spread of about 25 points.
Why 63034 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 63034, not a ranked or complete list of what matters most.
Density combined with diversity predicts Democratic voting. Non-Hispanic white share in 63034 is about 22%, about 50 points below the U.S. average of 72%. High college attainment predicts Democratic voting, and 63034 sits in the top quarter (about 41%, above 82% of zip codes). 63034 runs against the grain of Missouri, a Democratic-leaning pocket in a Republican-leaning state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 63034, MO sits in the top quarter nationally on this measure.
Why turnout in 63034 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 63034 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 65%, above 63% of zip codes. Homeowners vote more often than renters, and about 91% of households in 63034 own their home, compared to around 58% in nearby 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.