78629 leans heavily Republican by roughly 40 points: about 30% of voters vote Democratic and 70% Republican.
About 60% of adults in 78629 typically vote, near the U.S. average of about 62%. Among adults in 78629, ~18% vote Democratic, ~42% Republican, and ~40% don't vote. The map below shows estimated turnout by block group.
How 78629 compares
Among zip codes within 15 miles, 78629 is the least Republican-leaning.
78629 runs about 26 points more Republican than Texas as a whole.
Politics vary noticeably by block within 78629. The southwest side is the most Republican-leaning (R+70) and the north side is the least Republican-leaning (R+24), a spread of about 46 points.
Why 78629 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 78629, not a ranked or complete list of what matters most.
Areas with low college attainment vote Republican. About 14% of adults in 78629 hold a bachelor's degree, about 12 points below the Texas average of 26%.
Cancer-screening access and voter turnout
Places with low colon-cancer-screening access tend to turn out at a lower rate; 78629, TX sits in the bottom tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 78629 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78629 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 49%, about 11 points below the U.S. average of 60%. Renters vote less often than owners, and about 39% of households in 78629 rent, compared to around 21% in nearby zip codes. Low high-school completion lines up with lower turnout, and about 73% of adults in 78629 have completed high school, below 96% 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 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.