Plainville leans slightly Democratic by roughly 6 points: about 53% of voters vote Democratic and 47% Republican.
About 84% of adults in Plainville typically vote, above the U.S. average of about 62%. Among adults in Plainville, ~45% vote Democratic, ~39% Republican, and ~16% don't vote. The map below shows estimated turnout by block group.
How Plainville compares
Among cities within 25 miles, Plainville leans more Democratic than 68 of 155 neighbors.
Plainville runs about 19 points more Republican than Massachusetts as a whole.
Politics vary noticeably by neighborhood within Plainville. The east side runs the most Democratic (D+11) and the southwest side runs the most Republican (Even), a spread of about 11 points.
Why Plainville 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 Plainville, not a ranked or complete list of what matters most.
Dense areas vote Democratic. About 54% of residents in Plainville live in densely developed areas, about 18 points above the U.S. average of 36%. High college attainment predicts Democratic voting, and Plainville sits in the top quarter (about 45%, above 91% of cities).
Population density and Democratic lean
Places with high population density tend to lean Democratic; Plainville, MA sits in the top quarter nationally on this measure.
Why turnout in Plainville looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Plainville 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%. High high-school completion lines up with higher turnout, and about 96% of adults in Plainville have completed high school, above 86% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- North Attleboro, MA D+8
- Attleboro Falls, MA D+10
- Wrentham, MA D+9
- West Foxboro, MA D+13
- Cumberland, RI D+7
- Foxborough, MA D+20
- Mansfield Center, MA D+14
- Foxboro, MA D+13
- Attleboro, MA D+7
- Mansfield, MA D+14
Cities with Similar Populations
- Boonville, MO R+36
- Ambridge, PA D+6
- Pingree Grove, IL R+6
- Fayetteville, PA R+40
- Poplar Grove, IL R+19
- Monongahela, PA R+26
- Santa Teresa, NM R+4
- Port Salerno, FL R+19
- Terryville, NY R+21
- Union Park, FL D+5
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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.