77378 leans heavily Republican by roughly 42 points: about 29% of voters vote Democratic and 71% Republican.
About 58% of adults in 77378 typically vote, near the U.S. average of about 62%. Among adults in 77378, ~17% vote Democratic, ~41% Republican, and ~42% don't vote. The map below shows estimated turnout by block group.
How 77378 compares
Among zip codes within 15 miles, 77378 leans more Republican than 3 of 10 neighbors.
77378 runs about 28 points more Republican than Texas as a whole.
Politics vary noticeably by block within 77378. The northeast side is the most Republican-leaning (R+63) and the west side is the least Republican-leaning (R+15), a spread of about 48 points.
Why 77378 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 77378. The lean here lands roughly where demographic data alone would predict.
Cancer-screening access and voter turnout
Places with low colon-cancer-screening access tend to turn out at a lower rate; 77378, 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 77378 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 77378 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%. 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.