21659 leans heavily Republican by roughly 46 points: about 27% of voters vote Democratic and 73% Republican.
About 66% of adults in 21659 typically vote, near the U.S. average of about 62%. Among adults in 21659, ~18% vote Democratic, ~48% Republican, and ~34% don't vote. The map below shows estimated turnout by block group.
How 21659 compares
Among zip codes within 15 miles, 21659 leans more Republican than 12 of 15 neighbors.
21659 runs about 74 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21659 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 21659. The southeast side is the most Republican-leaning (R+50) and the southwest side is the least Republican-leaning (R+34), a spread of about 16 points.
Why 21659 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 21659, not a ranked or complete list of what matters most.
Areas with low college attainment vote Republican. About 11% of adults in 21659 hold a bachelor's degree, about 26 points below the Maryland average of 38%. 21659 runs against the grain of Maryland, a Republican-leaning pocket in a Democratic-leaning state.
Population density and Republican lean
Places with low population density tend to lean Republican; 21659, MD sits below the national average on this measure.
Why turnout in 21659 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21659 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 60%, below 60% 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 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.