64109 is a Democratic stronghold. About 87% of voters here vote Democratic and 13% Republican.
About 45% of adults in 64109 typically vote, below the U.S. average of about 62%. Among adults in 64109, ~39% vote Democratic, ~6% Republican, and ~55% don't vote. The map below shows estimated turnout by block group.
How 64109 compares
Among zip codes within 15 miles, 64109 leans more Democratic than 85 of 88 neighbors.
64109 runs about 92 points more Democratic than Missouri as a whole. Missouri leans Republican overall, while 64109 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 64109. The east side is the most Democratic-leaning (D+84) and the northwest side is the least Democratic-leaning (D+65), a spread of about 20 points.
Why 64109 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 64109, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 64109 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 52% of adults in 64109 have never been married, above 96% of zip codes. 64109 runs against the grain of Missouri, a Democratic-leaning pocket in a Republican-leaning state.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 64109, MO sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in 64109 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 64109 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 61% of households in 64109 rent, about 36 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 29% of adults in 64109 report food insecurity, 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.