37203 leans heavily Democratic by roughly 42 points: about 71% of voters vote Democratic and 29% Republican.
About 48% of adults in 37203 typically vote, below the U.S. average of about 62%. Among adults in 37203, ~34% vote Democratic, ~14% Republican, and ~52% don't vote. The map below shows estimated turnout by block group.
How 37203 compares
Among zip codes within 15 miles, 37203 leans more Democratic than 21 of 31 neighbors.
37203 runs about 71 points more Democratic than Tennessee as a whole. Tennessee leans Republican overall, while 37203 is one of the few Democratic-leaning pockets.
Politics vary noticeably by block within 37203. The south side is the most Democratic-leaning (D+63) and the east side is the least Democratic-leaning (D+17), a spread of about 46 points.
Why 37203 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 37203, not a ranked or complete list of what matters most.
Dense areas vote Democratic. More than 99% of residents in 37203 live in densely developed areas, about 63 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 37203 sits in the top quarter (about 70%, above 97% of zip codes). 37203 runs against the grain of Tennessee, a Democratic-leaning pocket in a Republican-leaning state.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 37203, TN sits in the top tenth 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 37203 looks the way it does
Renters vote less often than owners. About 78% of households in 37203 rent, about 53 points above the U.S. average of 25%. High-crime urban areas turn out at lower rates, and 37203 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.