Southborough leans heavily Democratic by roughly 30 points: about 65% of voters vote Democratic and 35% Republican.
About 85% of adults in Southborough typically vote, above the U.S. average of about 62%. Among adults in Southborough, ~55% vote Democratic, ~30% Republican, and ~15% don't vote. The map below shows estimated turnout by block group.
How Southborough compares
Among cities within 25 miles, Southborough leans more Democratic than 115 of 171 neighbors.
Southborough runs about 6 points more Democratic than Massachusetts as a whole.
Why Southborough 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 Southborough, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 76% of adults in Southborough hold a bachelor's degree, about 48 points above the U.S. average of 28%. Dense areas vote Democratic, and Southborough sits in the top fifth on density (about 48%, above 86% of cities).
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Southborough, 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 Southborough looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Southborough 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 80%, about 20 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Southborough have completed high school, above 90% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Fayville, MA D+31
- Southville, MA D+21
- Marlborough, MA D+21
- Ashland, MA D+29
- Westborough, MA D+31
- Hopkinton, MA D+26
- Framingham, MA D+32
- Northborough, MA D+24
- Hudson, MA D+15
- Holliston, MA D+22
Cities with Similar Populations
- Liberty, NC R+45
- Sullivan, MO R+53
- Fort Wainwright, AK R+22
- North Chelmsford, MA D+10
- Sutherlin, OR R+34
- Salem, IL R+52
- Rye Brook, NY D+19
- Arden Hills, MN D+31
- Paola, KS R+35
- Live Oak, CA R+27
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.