20171 leans heavily Democratic by roughly 38 points: about 69% of voters vote Democratic and 31% Republican.
About 76% of adults in 20171 typically vote, above the U.S. average of about 62%. Among adults in 20171, ~52% vote Democratic, ~24% Republican, and ~24% don't vote. The map below shows estimated turnout by block group.
How 20171 compares
Among zip codes within 15 miles, 20171 leans more Democratic than 36 of 52 neighbors.
20171 runs about 33 points more Democratic than Virginia as a whole.
Politics vary noticeably by block within 20171. The northwest side is the most Democratic-leaning (D+51) and the southeast side is the least Democratic-leaning (D+32), a spread of about 20 points.
Why 20171 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 20171, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 75% of adults in 20171 hold a bachelor's degree, about 47 points above the U.S. average of 28%. Dense areas vote Democratic, and 20171 sits in the top fifth on density (about 94%, above 90% of zip codes).
Population density and Democratic lean
Places with high population density tend to lean Democratic; 20171, VA sits in the top tenth nationally on this measure.
Why turnout in 20171 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 20171 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 75%, about 15 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in 20171 have completed high school, above 88% 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.