38139 leans Republican by roughly 28 points: about 36% of voters vote Democratic and 64% Republican.
About 94% of adults in 38139 typically vote, above the U.S. average of about 62%. Among adults in 38139, ~34% vote Democratic, ~60% Republican, and ~6% don't vote. The map below shows estimated turnout by block group.
How 38139 compares
Among zip codes within 15 miles, 38139 leans more Republican than 28 of 30 neighbors.
Politically, 38139 sits close to the rest of Tennessee.
Politics vary noticeably by block within 38139. The east side is the most Republican-leaning (R+37) and the northwest side is the least Republican-leaning (R+20), a spread of about 17 points.
Why 38139 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 38139, not a ranked or complete list of what matters most.
38139 votes Republican even though it is densely developed (about 89%, far above the Tennessee average of 21%). State and regional patterns outweigh the Democratic lean that density usually predicts here. A high family-household share predicts Republican voting, and about 86% of households in 38139 are family households, above 98% of zip codes.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; 38139, TN sits in the top tenth nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 38139 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 38139 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 76%, about 16 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 97% of households in 38139 own their home, compared to around 64% in nearby zip codes. High high-school completion lines up with higher turnout, and more than 99% of adults in 38139 have completed high school, above 98% of zip codes. 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 Tennessee Secretary of State, Division of 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.