Port Isabel leans slightly Republican by roughly 6 points: about 47% of voters vote Democratic and 53% Republican.
About 50% of adults in Port Isabel typically vote, below the U.S. average of about 62%. Among adults in Port Isabel, ~23% vote Democratic, ~26% Republican, and ~51% don't vote. The map below shows estimated turnout by block group.
How Port Isabel compares
Among cities within 25 miles, Port Isabel leans more Republican than 2 of 15 neighbors.
Port Isabel runs about 8 points more Democratic than Texas as a whole.
Politics vary noticeably by neighborhood within Port Isabel. The southeast side is the most split-leaning (R+22) and the south side is the least split-leaning (Even), a spread of about 21 points.
Why Port Isabel leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Port Isabel, not a ranked or complete list of what matters most.
Port Isabel votes Republican even though it is densely developed (about 52%, well above the Texas average of 35%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
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 Port Isabel, TX does.
Why turnout in Port Isabel looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Port Isabel 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 49%, about 11 points below the U.S. average of 60%. Renters vote less often than owners, and about 36% of households in Port Isabel rent, above 91% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- South Padre Island, TX R+22
- Laguna Vista, TX R+34
- Bayview, TX R+35
- Los Fresnos, TX R+12
- Indian Lake, TX R+16
- Brownsville, TX Even
- Olmito, TX R+10
- Arroyo Gardens, TX R+16
- Laureles, TX R+11
- Lozano, TX R+14
Cities with Similar Populations
- West Concord, MA D+53
- Boones Mill, VA R+48
- Mount Wolf, PA R+28
- St. James, NC R+27
- Rogersville, AL R+73
- Algona, IA R+34
- Mahanoy City, PA R+7
- Clayton, GA R+56
- Elba, AL R+46
- Bloomer, WI R+34
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.