78717 leans Democratic by roughly 18 points: about 59% of voters vote Democratic and 41% Republican.
About 67% of adults in 78717 typically vote, near the U.S. average of about 62%. Among adults in 78717, ~40% vote Democratic, ~27% Republican, and ~33% don't vote. The map below shows estimated turnout by block group.
How 78717 compares
Among zip codes within 15 miles, 78717 leans more Democratic than 12 of 34 neighbors.
78717 runs about 31 points more Democratic than Texas as a whole. Texas leans Republican overall, while 78717 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 78717. The southwest side is the most Democratic-leaning (D+27) and the east side is the least Democratic-leaning (D+8), a spread of about 19 points.
Why 78717 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 78717, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 70% of adults in 78717 hold a bachelor's degree, about 42 points above the U.S. average of 28%. Dense areas vote Democratic, and 78717 sits in the top fifth on density (about 83%, above 84% of zip codes). 78717 runs against the grain of Texas, a Democratic-leaning pocket in a Republican-leaning state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; 78717, TX sits in the top quarter nationally on this measure.
Why turnout in 78717 looks the way it does
Areas with high high-school completion turn out at higher rates. About 96% of adults in 78717 have completed high school, about 10 points above the Texas average of 86%. 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.