21666 leans Republican by roughly 24 points: about 38% of voters vote Democratic and 62% Republican.
About 91% of adults in 21666 typically vote, above the U.S. average of about 62%. Among adults in 21666, ~35% vote Democratic, ~57% Republican, and ~8% don't vote. The map below shows estimated turnout by block group.
How 21666 compares
Among zip codes within 15 miles, 21666 leans more Republican than 22 of 24 neighbors.
21666 runs about 52 points more Republican than Maryland as a whole. Maryland leans Democratic overall, while 21666 is one of the few Republican-leaning pockets.
Why 21666 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 21666, not a ranked or complete list of what matters most.
21666 votes against the grain of Maryland. Maryland leans Democratic overall, while 21666 runs about 52 points more Republican. A high family-household share predicts Republican voting, and about 74% of households in 21666 are family households, above 75% of zip codes.
Food insecurity and voter turnout
Places with low food insecurity tend to turn out at a higher rate; 21666, MD sits in the bottom tenth nationally on this measure. Food insecurity does not directly drive turnout; it reflects economic hardship, which lines up with lower voting.
Why turnout in 21666 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 21666 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 70%, about 10 points above the U.S. average of 60%. 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.