21555 is a Republican stronghold. About 16% of voters here vote Democratic and 84% Republican.
About 65% of adults in 21555 typically vote, near the U.S. average of about 62%. Among adults in 21555, ~10% vote Democratic, ~55% Republican, and ~35% don't vote. The map below shows estimated turnout by block group.
How 21555 compares
Among zip codes within 15 miles, 21555 is the most Republican-leaning.
21555 runs about 96 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21555 is one of the few Republican-leaning pockets.
Why 21555 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 21555, not a ranked or complete list of what matters most.
Areas with a high white share and below-average college attainment vote Republican. In 21555, about 98% of residents are non-Hispanic white, about 25 points above the U.S. average of 72%; about 16% of adults hold a bachelor's degree, about 21 points below the Maryland average of 38%. Rural areas vote Republican, and 21555 sits in the bottom quarter on density (about 5%, below 81% of zip codes). 21555 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; 21555, MD sits in the bottom quarter nationally on this measure.
Why turnout in 21555 looks the way it does
Turnout in 21555 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.