02451 leans heavily Democratic by roughly 36 points: about 68% of voters vote Democratic and 32% Republican.
About 70% of adults in 02451 typically vote, above the U.S. average of about 62%. Among adults in 02451, ~48% vote Democratic, ~22% Republican, and ~30% don't vote. The map below shows estimated turnout by block group.
How 02451 compares
Among zip codes within 15 miles, 02451 leans more Democratic than 31 of 110 neighbors.
02451 runs about 11 points more Democratic than Massachusetts as a whole.
Politics vary noticeably by block within 02451. The southeast side is the most Democratic-leaning (D+48) and the northwest side is the least Democratic-leaning (D+25), a spread of about 23 points.
Why 02451 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 02451, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 85% of residents in 02451 live in densely developed areas, about 48 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and 02451 sits in the top quarter (about 57%, above 93% of zip codes). A high never-married share predicts Democratic voting, and about 39% of adults in 02451 have never been married, above 85% of zip codes.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 02451, MA sits in the top tenth nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in 02451 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 02451 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%. 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 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.