21738 leans slightly Democratic by roughly 12 points: about 56% of voters vote Democratic and 44% Republican.
About 93% of adults in 21738 typically vote, above the U.S. average of about 62%. Among adults in 21738, ~52% vote Democratic, ~41% Republican, and ~7% don't vote. The map below shows estimated turnout by block group.
How 21738 compares
Among zip codes within 15 miles, 21738 leans more Democratic than 6 of 45 neighbors.
21738 runs about 18 points more Republican than Maryland as a whole.
Politics vary noticeably by block within 21738. The south side is the most Democratic-leaning (D+17) and the northeast side is the least Democratic-leaning (Even), a spread of about 17 points.
Why 21738 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 21738, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 75% of adults in 21738 hold a bachelor's degree, about 46 points above the U.S. average of 28%.
Cancer-screening access and voter turnout
Places with high colon-cancer-screening access tend to turn out at a higher rate; 21738, MD sits in the top quarter nationally on this measure. Cancer screening does not drive turnout; it reflects income, insurance, and healthcare access.
Why turnout in 21738 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21738 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 76%, about 16 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 98% of households in 21738 own their home, about 23 points above the U.S. average of 75%. High high-school completion lines up with higher turnout, and about 97% of adults in 21738 have completed high school, above 89% 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.