78839 leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 66% of adults in 78839 typically vote, near the U.S. average of about 62%. Among adults in 78839, ~35% vote Democratic, ~31% Republican, and ~34% don't vote. The map below shows estimated turnout by block group.
How 78839 compares
78839 runs about 19 points more Democratic than Texas as a whole. Texas leans Republican overall, while 78839 is one of the few Democratic-leaning pockets.
Why 78839 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 78839, not a ranked or complete list of what matters most.
Areas with many never-married adults vote Democratic. About 41% of adults in 78839 have never been married, well above similar-sized zip codes (around 26%). 78839 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; 78839, TX sits above the national average on this measure.
Why turnout in 78839 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78839 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 40%, about 13 points below the Texas average of 54%. 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.