78377 leans heavily Republican by roughly 34 points: about 33% of voters vote Democratic and 67% Republican.
About 64% of adults in 78377 typically vote, near the U.S. average of about 62%. Among adults in 78377, ~21% vote Democratic, ~43% Republican, and ~36% don't vote. The map below shows estimated turnout by block group.
How 78377 compares
78377 runs about 21 points more Republican than Texas as a whole.
Politics vary noticeably by block within 78377. The northeast side is the most Republican-leaning (R+50) and the south side is the least Republican-leaning (R+23), a spread of about 27 points.
Why 78377 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 78377, not a ranked or complete list of what matters most.
Areas with low college attainment vote Republican. About 11% of adults in 78377 hold a bachelor's degree, about 15 points below the Texas average of 26%. Car-dependent areas vote Republican, and about 83% of residents in 78377 drive to work alone, above 82% of zip codes.
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; 78377, TX sits in the bottom tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in 78377 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78377 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 46%, about 8 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.