Upper Marlboro is a Democratic stronghold. About 88% of voters here vote Democratic and 12% Republican.
About 78% of adults in Upper Marlboro typically vote, above the U.S. average of about 62%. Among adults in Upper Marlboro, ~68% vote Democratic, ~9% Republican, and ~23% don't vote. The map below shows estimated turnout by block group.
How Upper Marlboro compares
Among cities within 25 miles, Upper Marlboro leans more Democratic than 163 of 190 neighbors.
Upper Marlboro runs about 48 points more Democratic than Maryland as a whole.
Politics vary noticeably by neighborhood within Upper Marlboro. The northwest side is the most Democratic-leaning (D+84) and the southeast side is the least Democratic-leaning (D+21), a spread of about 63 points.
Why Upper Marlboro leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Upper Marlboro, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 54% of residents in Upper Marlboro live in densely developed areas, about 17 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Upper Marlboro sits in the top quarter (about 42%, above 89% of cities). A high never-married share predicts Democratic voting, and about 37% of adults in Upper Marlboro have never been married, above 90% of cities.
Paved land cover and Democratic lean
Places with extensive paved surfaces tend to lean Democratic; Upper Marlboro, 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 Upper Marlboro looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Upper Marlboro 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 64%, above 63% of cities. Homeowners vote more often than renters, and about 92% of households in Upper Marlboro own their home, about 17 points above the U.S. average of 75%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Brock Hall, MD D+82
- Marlboro Village, MD D+85
- Westphalia, MD D+79
- Kettering, MD D+86
- Largo, MD D+86
- Lake Arbor, MD D+87
- Forestville, MD D+82
- Summerfield, MD D+85
- Leon, MD D+52
- Rosaryville, MD D+77
Cities with Similar Populations
- King City, CA D+14
- Burtonsville, MD D+56
- New Hartford, NY R+4
- Discovery Bay, CA R+12
- Coweta, OK R+45
- Cleveland, MS D+22
- Seabrook, TX R+27
- Glen Carbon, IL D+3
- Lansdowne, PA D+68
- Clifton, VA D+19
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.