37406 is a Democratic stronghold. About 83% of voters here vote Democratic and 17% Republican.
About 53% of adults in 37406 typically vote, below the U.S. average of about 62%. Among adults in 37406, ~44% vote Democratic, ~9% Republican, and ~47% don't vote. The map below shows estimated turnout by block group.
How 37406 compares
Among zip codes within 15 miles, 37406 leans more Democratic than 31 of 32 neighbors.
37406 runs about 95 points more Democratic than Tennessee as a whole. Tennessee leans Republican overall, while 37406 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 37406. The southwest side is the most Democratic-leaning (D+84) and the northwest side is the least Democratic-leaning (D+34), a spread of about 50 points.
Why 37406 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 37406, not a ranked or complete list of what matters most.
Density combined with diversity predicts Democratic voting. Non-Hispanic white share in 37406 is about 24%, about 49 points below the U.S. average of 72%. A high never-married share predicts Democratic voting, and about 43% of adults in 37406 have never been married, above 91% of zip codes. 37406 runs against the grain of Tennessee, a Democratic-leaning pocket in a Republican-leaning state.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 37406, TN sits in the top quarter nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in 37406 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 37406 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 47%, about 9 points below the Tennessee average of 56%. Renters vote less often than owners, and about 52% of households in 37406 rent, about 27 points above the U.S. average of 25%. High-crime urban areas turn out at lower rates, and 37406 sits in the top 15% on a violent-crime measure. 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.