Holliston leans Democratic by roughly 22 points: about 61% of voters vote Democratic and 39% Republican.
About 89% of adults in Holliston typically vote, above the U.S. average of about 62%. Among adults in Holliston, ~54% vote Democratic, ~35% Republican, and ~11% don't vote. The map below shows estimated turnout by block group.
How Holliston compares
Among cities within 25 miles, Holliston leans more Democratic than 90 of 170 neighbors.
Politically, Holliston sits close to the rest of Massachusetts.
Politics vary noticeably by neighborhood within Holliston. The north side is the most Democratic-leaning (D+29) and the east side is the least Democratic-leaning (D+19), a spread of about 10 points.
Why Holliston 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 Holliston, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 66% of adults in Holliston hold a bachelor's degree, about 38 points above the U.S. average of 28%. Dense areas vote Democratic, and Holliston sits in the top fifth on density (about 46%, 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; Holliston, 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 Holliston looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Holliston 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 78%, about 18 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 97% of adults in Holliston have completed high school, above 87% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Medway, MA D+16
- Ashland, MA D+29
- Sherborn, MA D+43
- Harding, MA D+17
- Millis, MA D+12
- Hopkinton, MA D+26
- Milford, MA D+8
- North Milford, MA D+10
- Southville, MA D+21
- Framingham, MA D+32
Cities with Similar Populations
- Booneville, MS R+54
- Stone Ridge, VA D+23
- DeForest, WI D+17
- Hampton Bays, NY R+6
- Fairview, NJ D+4
- Verona, NJ D+15
- Greenville, PA R+35
- Kearney, MO R+33
- Galena, OH R+15
- Burley, ID R+54
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.