Herndon leans heavily Democratic by roughly 34 points: about 67% of voters vote Democratic and 33% Republican.
About 70% of adults in Herndon typically vote, above the U.S. average of about 62%. Among adults in Herndon, ~47% vote Democratic, ~23% Republican, and ~30% don't vote. The map below shows estimated turnout by block group.
How Herndon compares
Among cities within 25 miles, Herndon leans more Democratic than 85 of 177 neighbors.
Herndon runs about 28 points more Democratic than Virginia as a whole.
Politics vary noticeably by neighborhood within Herndon. The west side is the most Democratic-leaning (D+38) and the north side is the least Democratic-leaning (D+28), a spread of about 10 points.
Why Herndon leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Herndon, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 94% of residents in Herndon live in densely developed areas, about 58 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Herndon sits in the top quarter (about 61%, above 97% of cities). A high never-married share predicts Democratic voting, and about 32% of adults in Herndon have never been married, above 81% of cities.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Herndon, VA sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in Herndon looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Herndon 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 72%, about 12 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- McNair, VA D+46
- Reston, VA D+45
- Franklin Farm, VA D+36
- Dranesville, VA D+32
- Sterling, VA D+23
- Dulles Town Center, VA D+26
- Chantilly, VA D+21
- Great Falls, VA D+21
- Cascades, VA D+28
- Wolf Trap, VA D+36
Cities with Similar Populations
- Pikesville, MD D+35
- Shelby, NC R+18
- Whitney, NV D+16
- Rosenberg, TX D+3
- Urbandale, IA D+7
- Clarkston, MI R+15
- Rancho Palos Verdes, CA D+18
- Shakopee, MN D+4
- Rexburg, ID R+31
- Issaquah, WA D+42
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.