78045 leans slightly Republican by roughly 8 points: about 46% of voters vote Democratic and 54% Republican.
About 54% of adults in 78045 typically vote, below the U.S. average of about 62%. Among adults in 78045, ~25% vote Democratic, ~29% Republican, and ~46% don't vote. The map below shows estimated turnout by block group.
How 78045 compares
Among zip codes within 15 miles, 78045 is the most Republican-leaning.
78045 runs about 7 points more Democratic than Texas as a whole.
Politics vary noticeably by block within 78045. The north side is the most Republican-leaning (R+44) and the south side is the least Republican-leaning (R+4), a spread of about 41 points.
Why 78045 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 78045, not a ranked or complete list of what matters most.
78045 votes Republican even though it is densely developed (about 80%, far above the Texas average of 35%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 82% of households in 78045 are family households, above 95% of zip codes.
High-school completion, developed land, and voter turnout
Places that combine low high-school-completion share and a heavily developed built environment tend to turn out at a lower rate, as 78045, TX does.
Why turnout in 78045 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 78045 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 26%, about 8 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.