21864 leans heavily Republican by roughly 32 points: about 34% of voters vote Democratic and 66% Republican.
About 80% of adults in 21864 typically vote, above the U.S. average of about 62%. Among adults in 21864, ~27% vote Democratic, ~53% Republican, and ~20% don't vote. The map below shows estimated turnout by block group.
How 21864 compares
Among zip codes within 15 miles, 21864 leans more Republican than 11 of 13 neighbors.
21864 runs about 60 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21864 is one of the few Republican-leaning pockets.
Why 21864 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 21864, not a ranked or complete list of what matters most.
Rural areas vote Republican. About 5% of residents in 21864 live in densely developed areas, about 38 points below the Maryland average of 43%. Low college attainment predicts Republican voting, and 21864 sits in the bottom quarter (about 15%, below 80% of zip codes). 21864 runs against the grain of Maryland, a Republican-leaning pocket in a Democratic-leaning state.
Population density, never-married share, and Republican lean
Places that combine low population density and a never-married-heavy adult population tend to lean Republican, as 21864, MD does.
Why turnout in 21864 looks the way it does
Turnout in 21864 sits close to the national pattern. Routine healthcare access, homeownership, education, and food security all land near their national averages here. 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 Maryland State Board 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.