78217 leans slightly Democratic by roughly 14 points: about 57% of voters vote Democratic and 43% Republican.
About 50% of adults in 78217 typically vote, below the U.S. average of about 62%. Among adults in 78217, ~29% vote Democratic, ~22% Republican, and ~49% don't vote. The map below shows estimated turnout by block group.
How 78217 compares
Among zip codes within 15 miles, 78217 leans more Democratic than 21 of 52 neighbors.
78217 runs about 27 points more Democratic than Texas as a whole. Texas leans Republican overall, while 78217 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 78217. The south side is the most Democratic-leaning (D+27) and the north side is the least Democratic-leaning (D+4), a spread of about 22 points.
Why 78217 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 78217, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 96% of residents in 78217 live in densely developed areas, about 60 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 35% of adults in 78217 have never been married, above 80% of zip codes. 78217 runs against the grain of Texas, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 78217, TX 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 78217 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78217 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The uninsured rate here is about 20%, about 10 points above the U.S. average of 10%. Renters vote less often than owners, and about 55% of households in 78217 rent, about 30 points above the U.S. average of 25%. 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 Texas Secretary of State, Elections Division, 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.