21084 leans heavily Republican by roughly 38 points: about 31% of voters vote Democratic and 69% Republican.
About 95% of adults in 21084 typically vote, above the U.S. average of about 62%. Among adults in 21084, ~30% vote Democratic, ~66% Republican, and ~4% don't vote. The map below shows estimated turnout by block group.
How 21084 compares
Among zip codes within 15 miles, 21084 leans more Republican than 24 of 33 neighbors.
21084 runs about 67 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21084 is one of the few Republican-leaning pockets.
Politics vary noticeably by block within 21084. The northeast side is the most Republican-leaning (R+48) and the southwest side is the least Republican-leaning (R+31), a spread of about 17 points.
Why 21084 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 21084, not a ranked or complete list of what matters most.
21084 votes against the grain of Maryland. Maryland leans Democratic overall, while 21084 runs about 67 points more Republican. A high family-household share predicts Republican voting, and about 78% of households in 21084 are family households, above 87% of zip codes.
Homeownership and voter turnout
Places with homeowner-heavy households tend to turn out at a higher rate; 21084, MD sits in the top tenth nationally on this measure.
Why turnout in 21084 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21084 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 69%, about 9 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 95% of households in 21084 own their home, about 20 points above the U.S. average of 75%. High high-school completion lines up with higher turnout, and about 97% of adults in 21084 have completed high school, above 86% 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.