Massachusetts Middlesex and Worcester District

State Legislative District Profile (Upper Chamber)

Overview

District ID
ma-sd-d12
State
Massachusetts
Chamber
Upper chamber (state senate)
District Code
D12
Land Area
190.3 sq mi
Water Area
8.01 sq mi

Boundary

Boundary of Massachusetts Middlesex and Worcester District

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
Middlesex County149.85 sq mi78.7%18.3%
Worcester County40.45 sq mi21.3%2.7%

Showing all 2 counties

Places

PlaceOverlapShare of district landShare of place land
Marlborough city20.86 sq mi11.0%100.0%
Hudson CDP5.75 sq mi3.0%100.0%
Devens CDP5.69 sq mi3.0%83.8%
Maynard CDP5.21 sq mi2.7%100.0%
Cochituate CDP3.68 sq mi1.9%96.6%
Littleton Common CDP3.54 sq mi1.9%100.0%
Cordaville CDP1.82 sq mi1.0%100.0%
Ayer CDP1.33 sq mi0.7%100.0%

Showing all 8 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
MA District 3124,05769.6%15.9%69.2%
MA District 543,62324.5%5.6%23.4%
MA District 210,4505.9%1.3%7.4%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
129,346
Active Voters
104,833 (81.0%)

Party Registration

PartyVotersShare
Democratic29,80323.0%
Republican<10—
Unaffiliated00.0%
Other parties89,52269.2%
No party recorded<10—

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202624,603 (19.0%)0 (0.0%)0 (0.0%)
2023–202496,733 (74.8%)26,412 (20.4%)17,252 (13.3%)
2021–202274,529 (57.6%)21,508 (16.6%)6,559 (5.1%)
2019–202090,172 (69.7%)49,917 (38.6%)9,309 (7.2%)
2017–201871,587 (55.3%)18,564 (14.4%)6,198 (4.8%)
2015–201677,016 (59.5%)30,479 (23.6%)15,178 (11.7%)
2013–201452,574 (40.6%)10,743 (8.3%)2,910 (2.2%)
2011–201265,644 (50.8%)6,061 (4.7%)9,095 (7.0%)

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
178,817 (± 59)
Median Age
42.1
Median Household Income
$138,159 (± $3,576)
High School Graduate or Higher (age 25+)
93.9%
Bachelor's Degree or Higher (age 25+)
61.9%

Population by Age

GroupPeopleShare
Under 1839,83522.3%
18 to 64109,06661.0%
65 and over29,91616.7%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)14,6438.2%
White, not Hispanic123,48369.1%
Black, not Hispanic4,8982.7%
Asian, not Hispanic19,08310.7%
American Indian / Alaska Native, not Hispanic1030.1%
Native Hawaiian / Pacific Islander, not Hispanic810.0%
Some other race, not Hispanic3,2651.8%
Two or more races, not Hispanic13,2617.4%

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
161,210
Citizen Voting Age Population (CVAP)
123,399

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic149,90293.0%
Hispanic11,3137.0%
White126,47978.5%
Black4,0372.5%
Asian13,7768.5%
American Indian / Alaska Native1390.1%
Native Hawaiian / Pacific Islander370.0%
Two or More Races3560.2%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic115,95294.0%
Hispanic7,4496.0%
White101,33582.1%
Black3,5082.8%
Asian10,4118.4%
American Indian / Alaska Native4530.4%
Native Hawaiian / Pacific Islander370.0%
Two or More Races2260.2%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).