21658 leans Republican by roughly 16 points: about 42% of voters vote Democratic and 58% Republican.
About 93% of adults in 21658 typically vote, above the U.S. average of about 62%. Among adults in 21658, ~39% vote Democratic, ~54% Republican, and ~7% don't vote. The map below shows estimated turnout by block group.
How 21658 compares
Among zip codes within 15 miles, 21658 leans more Republican than 8 of 16 neighbors.
21658 runs about 45 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21658 is one of the few Republican-leaning pockets.
Why 21658 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 21658, not a ranked or complete list of what matters most.
21658 votes against the grain of Maryland. Maryland leans Democratic overall, while 21658 runs about 45 points more Republican. A high family-household share predicts Republican voting, and about 80% of households in 21658 are family households, above 91% of zip codes.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; 21658, MD sits in the top tenth nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in 21658 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21658 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 72%, about 12 points above the U.S. average of 60%. Homeowners vote more often than renters, and about 90% of households in 21658 own their home, about 15 points above the U.S. average of 75%. 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.