21648 leans heavily Republican by roughly 50 points: about 25% of voters vote Democratic and 75% Republican.
About 73% of adults in 21648 typically vote, above the U.S. average of about 62%. Among adults in 21648, ~18% vote Democratic, ~55% Republican, and ~27% don't vote. The map below shows estimated turnout by block group.
How 21648 compares
Among zip codes within 15 miles, 21648 leans more Republican than 9 of 12 neighbors.
21648 runs about 78 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21648 is one of the few Republican-leaning pockets.
Why 21648 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 21648, not a ranked or complete list of what matters most.
21648 votes against the grain of Maryland. Maryland leans Democratic overall, while 21648 runs about 78 points more Republican. Rural areas vote Republican, and 21648 sits in the bottom quarter on density (about 3%, below 92% of zip codes). A high family-household share predicts Republican voting, and about 77% of households in 21648 are family households, above 85% of zip codes.
Walkability and Republican lean
Places with a low walkability score tend to lean Republican; 21648, MD sits in the bottom tenth 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 21648 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21648 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 64%, above 62% of zip codes. Homeowners vote more often than renters, and about 97% of households in 21648 own their home, about 22 points above the U.S. average of 75%. 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.