66104 is a Democratic stronghold. About 76% of voters here vote Democratic and 24% Republican.
About 43% of adults in 66104 typically vote, below the U.S. average of about 62%. Among adults in 66104, ~33% vote Democratic, ~10% Republican, and ~57% don't vote. The map below shows estimated turnout by block group.
How 66104 compares
Among zip codes within 15 miles, 66104 leans more Democratic than 66 of 78 neighbors.
66104 runs about 67 points more Democratic than Kansas as a whole. Kansas leans Republican overall, while 66104 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 66104. The east side is the most Democratic-leaning (D+74) and the northwest side is the least Democratic-leaning (D+28), a spread of about 45 points.
Why 66104 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 66104, not a ranked or complete list of what matters most.
66104 votes against the grain of Kansas. Kansas leans Republican overall, while 66104 runs about 67 points more Democratic. Density combined with diversity predicts Democratic voting, and non-Hispanic white share in 66104 is about 21%, compared to around 42% in nearby zip codes. A high never-married share predicts Democratic voting, and about 39% of adults in 66104 have never been married, above 86% of zip codes.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 66104, KS sits in the top quarter nationally on this measure.
Why turnout in 66104 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 66104 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 48%, about 15 points below the Kansas average of 63%. High food insecurity lines up with lower turnout, and about 29% of adults in 66104 report food insecurity, above 93% of zip codes. Low high-school completion lines up with lower turnout, and about 78% of adults in 66104 have completed high school, below 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 Kansas 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.