20109 leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.
About 50% of adults in 20109 typically vote, below the U.S. average of about 62%. Among adults in 20109, ~30% vote Democratic, ~20% Republican, and ~50% don't vote. The map below shows estimated turnout by block group.
How 20109 compares
Among zip codes within 15 miles, 20109 leans more Democratic than 17 of 33 neighbors.
20109 runs about 15 points more Democratic than Virginia as a whole.
Politics vary noticeably by block within 20109. The west side is the most Democratic-leaning (D+28) and the east side is the least Democratic-leaning (D+16), a spread of about 12 points.
Why 20109 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 20109, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 91% of residents in 20109 live in densely developed areas, about 55 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 43% of adults in 20109 have never been married, above 91% of zip codes.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 20109, VA 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 20109 looks the way it does
Areas with limited routine healthcare access turn out at lower rates. 20109 is in the bottom quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. Renters vote less often than owners, and about 54% of households in 20109 rent, compared to around 15% in nearby zip codes. Crowded housing lines up with lower turnout, and about 8% of homes in 20109 have more than one occupant per room, above 93% 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 Virginia Department 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.