Jefferson County leans slightly Democratic by roughly 8 points: about 54% of voters vote Democratic and 46% Republican.
About 55% of adults in Jefferson County typically vote, below the U.S. average of about 62%. Among adults in Jefferson County, ~30% vote Democratic, ~25% Republican, and ~45% don't vote. The map below shows estimated turnout by block group.
How Jefferson County compares
Among counties within 50 miles, Jefferson County is the most Democratic-leaning.
Jefferson County runs about 22 points more Democratic than Texas as a whole. Texas leans Republican overall, while Jefferson County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Jefferson County. The north side runs the most Democratic (D+62) and the southwest side runs the most Republican (R+72), a spread of about 135 points.
Why Jefferson County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Jefferson County, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 81% of residents in Jefferson County live in densely developed areas, about 45 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 35% of adults in Jefferson County have never been married, above 84% of counties. Jefferson County runs against the grain of Texas, a Democratic-leaning pocket in a Republican-leaning state.
Population density and Democratic lean
Places with high population density tend to lean Democratic; Jefferson County, TX sits in the top tenth nationally on this measure.
Why turnout in Jefferson County looks the way it does
Areas with limited routine healthcare access turn out at lower rates. Jefferson County is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 36% of households in Jefferson County rent, compared to around 18% in nearby counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Orange County, TX R+59
- Hardin County, TX R+68
- Chambers County, TX R+58
- Jasper County, TX R+54
- Newton County, TX R+61
- Calcasieu Parish, LA R+29
- Cameron Parish, LA R+86
- Liberty County, TX R+50
- Tyler County, TX R+70
- Beauregard Parish, LA R+70
Counties with Similar Populations
- Yakima County, WA R+6
- St. Clair County, IL D+13
- Cumberland County, PA R+9
- Clay County, MO R+7
- McLennan County, TX R+19
- Harford County, MD R+4
- Kalamazoo County, MI D+17
- Forsyth County, GA R+22
- Weber County, UT R+21
- Marin County, CA D+48
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.