38138 leans slightly Republican by roughly 12 points: about 44% of voters vote Democratic and 56% Republican.
About 86% of adults in 38138 typically vote, above the U.S. average of about 62%. Among adults in 38138, ~38% vote Democratic, ~48% Republican, and ~14% don't vote. The map below shows estimated turnout by block group.
How 38138 compares
Among zip codes within 15 miles, 38138 leans more Republican than 31 of 37 neighbors.
38138 runs about 17 points more Democratic than Tennessee as a whole.
Politics vary noticeably by block within 38138. The northwest side is the most Republican-leaning (R+17) and the south side is the least Republican-leaning (R+6), a spread of about 11 points.
Why 38138 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 38138, not a ranked or complete list of what matters most.
38138 votes Republican even though it is densely developed (about 91%, far above the Tennessee average of 21%). Here an older population outweighs the Democratic lean that density usually predicts.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; 38138, 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 38138 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 38138 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 73%, about 13 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 98% of adults in 38138 have completed high school, above 94% 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.