Jefferson County leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 70% of adults in Jefferson County typically vote, above the U.S. average of about 62%. Among adults in Jefferson County, ~42% vote Democratic, ~28% Republican, and ~30% 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 50 points more Democratic than Alabama as a whole. Alabama leans Republican overall, while Jefferson County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Jefferson County. The southwest side runs the most Democratic (D+35) and the southeast side runs the most Republican (R+22), a spread of about 57 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 74% of residents in Jefferson County live in densely developed areas, about 38 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Jefferson County sits in the top quarter (about 37%, above 88% of counties). Jefferson County runs against the grain of Alabama, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Jefferson County, AL sits in the top quarter nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in Jefferson County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Jefferson County is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 58%, below 57% of counties. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Shelby County, AL R+36
- St. Clair County, AL R+65
- Blount County, AL R+79
- Walker County, AL R+72
- Bibb County, AL R+57
- Talladega County, AL R+27
- Cullman County, AL R+76
- Chilton County, AL R+69
- Tuscaloosa County, AL R+9
- Coosa County, AL R+26
Counties with Similar Populations
- Bernalillo County, NM D+21
- Tulsa County, OK Even
- Providence County, RI D+20
- District of Columbia, DC D+80
- Utah County, UT R+36
- Kent County, MI D+10
- Arapahoe County, CO D+22
- Will County, IL D+6
- Bucks County, PA Even
- Monmouth County, NJ R+8
Sources and methodology
Precinct-level voting records used to fit the model come from Alabama Secretary of State, Elections, 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.