Overview
- District ID
- ma-sd-d31
- State
- Massachusetts
- Chamber
- Upper chamber (state senate)
- District Code
- D31
- Land Area
- 142.1 sq mi
- Water Area
- 206.9 sq mi
Boundary
Boundary as GeoJSON
Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.
Counties
Showing all 2 counties
Places
Showing all 12 places
Overlapping Congressional Districts
| Congressional district | Population in both | Share of this district's population | Share of the congressional district's population | Share of this district's land |
|---|
| MA District 8 | 91,793 | 53.2% | 11.8% | 29.4% |
| MA District 9 | 80,710 | 46.8% | 10.3% | 70.6% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 141,034
- Active Voters
- 128,599 (91.2%)
Party Registration
| Party | Voters | Share |
|---|
| Democratic | 29,248 | 20.7% |
| Republican | <10 | — |
| Unaffiliated | 0 | 0.0% |
| Other parties | 96,260 | 68.3% |
| No party recorded | <10 | — |
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 27,512 (19.5%) | 0 (0.0%) | 0 (0.0%) |
| 2023–2024 | 107,933 (76.5%) | 24,576 (17.4%) | 23,927 (17.0%) |
| 2021–2022 | 81,993 (58.1%) | 19,632 (13.9%) | 12,053 (8.5%) |
| 2019–2020 | 103,213 (73.2%) | 47,371 (33.6%) | 13,060 (9.3%) |
| 2017–2018 | 77,928 (55.3%) | 17,011 (12.1%) | 10,393 (7.4%) |
| 2015–2016 | 88,156 (62.5%) | 29,636 (21.0%) | 21,798 (15.5%) |
| 2013–2014 | 61,165 (43.4%) | 11,769 (8.3%) | 4,656 (3.3%) |
| 2011–2012 | 76,546 (54.3%) | 6,448 (4.6%) | 11,583 (8.2%) |
Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.
Browse the voter list for this district (premium access; sign-in required)
Source: Civitech voter file snapshot as of 12/07/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".
Demographics
- Total Population
- 174,143 (± 62)
- Median Age
- 45.8
- Median Household Income
- $129,107 (± $4,699)
- High School Graduate or Higher (age 25+)
- 96.4%
- Bachelor's Degree or Higher (age 25+)
- 57.5%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 34,965 | 20.1% |
| 18 to 64 | 101,820 | 58.5% |
| 65 and over | 37,358 | 21.5% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 5,350 | 3.1% |
| White, not Hispanic | 153,148 | 87.9% |
| Black, not Hispanic | 2,883 | 1.7% |
| Asian, not Hispanic | 6,662 | 3.8% |
| American Indian / Alaska Native, not Hispanic | 54 | 0.0% |
| Native Hawaiian / Pacific Islander, not Hispanic | 22 | 0.0% |
| Some other race, not Hispanic | 1,213 | 0.7% |
| Two or more races, not Hispanic | 4,811 | 2.8% |
Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.
Citizen Voting Age Population
- Total Citizen Population
- 169,105
- Citizen Voting Age Population (CVAP)
- 134,503
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 164,347 | 97.2% |
| Hispanic | 4,760 | 2.8% |
| White | 153,858 | 91.0% |
| Black | 2,962 | 1.8% |
| Asian | 5,001 | 3.0% |
| American Indian / Alaska Native | 53 | 0.0% |
| Native Hawaiian / Pacific Islander | 22 | 0.0% |
| Two or More Races | 87 | 0.1% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 131,396 | 97.7% |
| Hispanic | 3,107 | 2.3% |
| White | 124,166 | 92.3% |
| Black | 2,410 | 1.8% |
| Asian | 4,395 | 3.3% |
| American Indian / Alaska Native | 416 | 0.3% |
| Native Hawaiian / Pacific Islander | 23 | 0.0% |
| Two or More Races | 50 | 0.0% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
