78237 leans heavily Democratic by roughly 32 points: about 66% of voters vote Democratic and 34% Republican.
About 32% of adults in 78237 typically vote, below the U.S. average of about 62%. Among adults in 78237, ~21% vote Democratic, ~11% Republican, and ~68% don't vote. The map below shows estimated turnout by block group.
How 78237 compares
Among zip codes within 15 miles, 78237 leans more Democratic than 41 of 54 neighbors.
78237 runs about 46 points more Democratic than Texas as a whole. Texas leans Republican overall, while 78237 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 78237. The north side is the most Democratic-leaning (D+38) and the southwest side is the least Democratic-leaning (D+25), a spread of about 12 points.
Why 78237 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 78237, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 99% of residents in 78237 live in densely developed areas, about 62 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 39% of adults in 78237 have never been married, above 86% of zip codes. 78237 runs against the grain of Texas, a Democratic-leaning pocket in a Republican-leaning state.
Preventive-care access and voter turnout
Places with limited routine preventive-care access tend to turn out at a lower rate; 78237, 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 78237 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78237 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 36%, about 18 points below the Texas average of 54%. Renters vote less often than owners, and about 39% of households in 78237 rent, compared to around 61% in nearby zip codes. Low high-school completion lines up with lower turnout, and about 65% of adults in 78237 have completed high school, in the bottom fraction 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.