01603 leans Democratic by roughly 24 points: about 62% of voters vote Democratic and 38% Republican.
About 51% of adults in 01603 typically vote, below the U.S. average of about 62%. Among adults in 01603, ~31% vote Democratic, ~19% Republican, and ~50% don't vote. The map below shows estimated turnout by block group.
How 01603 compares
Among zip codes within 15 miles, 01603 leans more Democratic than 35 of 45 neighbors.
Politically, 01603 sits close to the rest of Massachusetts.
Politics vary noticeably by block within 01603. The northeast side is the most Democratic-leaning (D+35) and the south side is the least Democratic-leaning (D+15), a spread of about 20 points.
Why 01603 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 01603, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 89% of residents in 01603 live in densely developed areas, about 53 points above the U.S. average of 36%. A high never-married share predicts Democratic voting, and about 43% of adults in 01603 have never been married, above 90% of zip codes.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; 01603, 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 01603 looks the way it does
Renters vote less often than owners. About 54% of households in 01603 rent, about 29 points above the U.S. average of 25%. High food insecurity lines up with lower turnout, and about 26% of adults in 01603 report food insecurity, above 90% of zip codes. 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.