Dennis leans Democratic by roughly 20 points: about 60% of voters vote Democratic and 40% Republican.
About 93% of adults in Dennis typically vote, above the U.S. average of about 62%. Among adults in Dennis, ~56% vote Democratic, ~37% Republican, and ~7% don't vote. The map below shows estimated turnout by block group.
How Dennis compares
Among cities within 25 miles, Dennis leans more Democratic than 31 of 55 neighbors.
Dennis runs about 5 points more Republican than Massachusetts as a whole.
Politics vary noticeably by neighborhood within Dennis. The northwest side is the most Democratic-leaning (D+27) and the northeast side is the least Democratic-leaning (D+16), a spread of about 12 points.
Why Dennis 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 Dennis, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 49% of adults in Dennis hold a bachelor's degree, about 20 points above the U.S. average of 28%. Dense areas vote Democratic, and Dennis sits in the top fifth on density (about 67%, above 91% of cities).
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Dennis, MA 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 Dennis looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Dennis 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 77%, about 17 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 99% of adults in Dennis have completed high school, above 97% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- East Dennis, MA D+12
- South Dennis, MA D+16
- Yarmouth Port, MA D+20
- South Yarmouth, MA D+19
- West Dennis, MA D+23
- Northwest Harwich, MA D+17
- Dennis Port, MA D+17
- West Yarmouth, MA D+11
- Barnstable, MA D+16
- Brewster, MA D+29
Cities with Similar Populations
- West Monroe, NY R+34
- Belgrade, ME D+7
- Lincoln, MO R+62
- Wagram, NC R+3
- Brandon, WI R+49
- Norwood, NY R+24
- Junction, TX R+57
- Ucon, ID R+66
- Gold Hill, NC R+68
- Mount Pleasant Mills, PA R+68
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Sources and methodology
Precinct-level voting records used to fit the model come from Massachusetts Secretary of the Commonwealth, 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.