77703 is a Democratic stronghold. About 82% of voters here vote Democratic and 18% Republican.
About 48% of adults in 77703 typically vote, below the U.S. average of about 62%. Among adults in 77703, ~39% vote Democratic, ~9% Republican, and ~52% don't vote. The map below shows estimated turnout by block group.
How 77703 compares
Among zip codes within 15 miles, 77703 is the most Democratic-leaning.
77703 runs about 78 points more Democratic than Texas as a whole. Texas leans Republican overall, while 77703 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 77703. The northeast side is the most Democratic-leaning (D+77) and the southwest side is the least Democratic-leaning (D+41), a spread of about 35 points.
Why 77703 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 77703, not a ranked or complete list of what matters most.
Density combined with diversity predicts Democratic voting. Non-Hispanic white share in 77703 is about 6%, about 66 points below the U.S. average of 72%. A high never-married share predicts Democratic voting, and about 45% of adults in 77703 have never been married, above 92% of zip codes. 77703 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; 77703, 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 77703 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 77703 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 34%, about 19 points below the Texas average of 54%. Renters vote less often than owners, and about 55% of households in 77703 rent, compared to around 33% in nearby zip codes. High-crime urban areas turn out at lower rates, and 77703 sits in the top 15% on a violent-crime measure. 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.