21521 is a Republican stronghold. About 19% of voters here vote Democratic and 81% Republican.
About 50% of adults in 21521 typically vote, below the U.S. average of about 62%. Among adults in 21521, ~10% vote Democratic, ~40% Republican, and ~50% don't vote. The map below shows estimated turnout by block group.
How 21521 compares
Among zip codes within 15 miles, 21521 leans more Republican than 16 of 22 neighbors.
21521 runs about 92 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21521 is one of the few Republican-leaning pockets.
Why 21521 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 21521, not a ranked or complete list of what matters most.
Areas with a high white share and below-average college attainment vote Republican. In 21521, about 99% of residents are non-Hispanic white, about 26 points above the U.S. average of 72%; about 8% of adults hold a bachelor's degree, about 30 points below the Maryland average of 38%. 21521 runs against the grain of Maryland, a Republican-leaning pocket in a Democratic-leaning state.
Local retail density and voter turnout
Places with sparse local retail within a mile tend to turn out at a lower rate; 21521, MD sits in the bottom tenth nationally on this measure. Nearby retail does not change how people vote; it reflects how urban and built-up a place is.
Why turnout in 21521 looks the way it does
Turnout in 21521 sits close to the national pattern. 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.