21742 leans slightly Republican by roughly 10 points: about 45% of voters vote Democratic and 55% Republican.
About 72% of adults in 21742 typically vote, above the U.S. average of about 62%. Among adults in 21742, ~32% vote Democratic, ~40% Republican, and ~28% don't vote. The map below shows estimated turnout by block group.
How 21742 compares
Among zip codes within 15 miles, 21742 leans more Republican than 2 of 27 neighbors.
21742 runs about 38 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21742 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 21742. The southwest side runs the most Democratic (D+5) and the northeast side runs the most Republican (R+43), a spread of about 48 points.
Why 21742 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 21742, not a ranked or complete list of what matters most.
21742 votes against the grain of Maryland. Maryland leans Democratic overall, while 21742 runs about 38 points more Republican. Dense places usually vote Democratic, but 21742 runs against that pattern.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 21742, MD sits in the top quarter nationally on this measure. Paved ground does not change how people vote; it mostly reflects how urban and built-up a place is.
Why turnout in 21742 looks the way it does
Turnout in 21742 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.