21133 is a Democratic stronghold. About 88% of voters here vote Democratic and 12% Republican.
About 69% of adults in 21133 typically vote, above the U.S. average of about 62%. Among adults in 21133, ~60% vote Democratic, ~8% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How 21133 compares
Among zip codes within 15 miles, 21133 leans more Democratic than 48 of 59 neighbors.
21133 runs about 48 points more Democratic than Maryland as a whole.
Politics vary noticeably by block within 21133. The east side is the most Democratic-leaning (D+81) and the west side is the least Democratic-leaning (D+69), a spread of about 12 points.
Why 21133 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 21133, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 78% of residents in 21133 live in densely developed areas, about 41 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 21133 sits in the top quarter (about 35%, above 75% of zip codes). A high never-married share predicts Democratic voting, and about 36% of adults in 21133 have never been married, above 81% of zip codes.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 21133, 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 21133 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21133 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 60%, below 60% 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.