Massachusetts State Senate seat · lines in effect since 2022
Massachusetts State Senate: Third Middlesex District
A district of about 176,000 people, 66% of adults with a bachelor's degree. It votes D+44.9 relative to the nation for president.
Where it sits among all 40 seats
Every Massachusetts State Senate seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Who lives here, compared
Grey bars show the spread of all 40 seats. Small marks are other seats in Massachusetts. The black marker is District D15.
Higher than 92% of seats.
Lower than 85% of seats.
Lower than 56% of seats.
Higher than 59% of seats.
Higher than 87% of seats.
Less dense than 51% of seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean.
District D1360% college gradsD+42.6Held DDistrict D12
62% college gradsD+43.3Held DDistrict D16
58% college gradsD+34.5Held DDistrict D23
57% college gradsD+34.4Held D
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Who has held it
These lines took effect in 2022.
- Michael J. Barrett (D)
2023– · Won 2022 by 97.4, 2024 unopposed, 2026 unopposed
Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)