78578 leans Republican by roughly 16 points: about 42% of voters vote Democratic and 58% Republican.
About 56% of adults in 78578 typically vote, below the U.S. average of about 62%. Among adults in 78578, ~24% vote Democratic, ~32% Republican, and ~44% don't vote. The map below shows estimated turnout by block group.
How 78578 compares
78578 sits in a sparsely populated area with few comparable zip codes nearby.
Politically, 78578 sits close to the rest of Texas.
Politics vary noticeably by block within 78578. The northwest side is the most split-leaning (R+34) and the east side is the least split-leaning (Even), a spread of about 34 points.
Why 78578 leans the way it does
Density, race composition, education, and family structure all sit close to their national averages in 78578. 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; 78578, 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 78578 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78578 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 29%, about 11 points above the Texas average of 19%. 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.