21230 is a Democratic stronghold. About 79% of voters here vote Democratic and 21% Republican.
About 68% of adults in 21230 typically vote, above the U.S. average of about 62%. Among adults in 21230, ~54% vote Democratic, ~14% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How 21230 compares
Among zip codes within 15 miles, 21230 leans more Democratic than 47 of 69 neighbors.
21230 runs about 28 points more Democratic than Maryland as a whole.
Politics vary noticeably by block within 21230. The north side is the most Democratic-leaning (D+73) and the west side is the least Democratic-leaning (D+25), a spread of about 48 points.
Why 21230 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 21230, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 92% of residents in 21230 live in densely developed areas, about 56 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 21230 sits in the top quarter (about 55%, above 92% of zip codes). A high never-married share predicts Democratic voting, and about 49% of adults in 21230 have never been married, above 94% of zip codes.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; 21230, MD sits in the top tenth 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 21230 looks the way it does
Turnout in 21230 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.