Massachusetts Fourth Middlesex District

State Legislative District Profile (Upper Chamber)

Overview

District ID
ma-sd-d16
State
Massachusetts
Chamber
Upper chamber (state senate)
District Code
D16
Land Area
65.1 sq mi
Water Area
1.54 sq mi

Boundary

Boundary of Massachusetts Fourth Middlesex District

Boundary as GeoJSON

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

Counties

CountyOverlapShare of district landShare of county land
Middlesex County65.13 sq mi100.0%8.0%

Showing all 1 county

Places

PlaceOverlapShare of district landShare of place land
Woburn city12.65 sq mi19.4%100.0%
Burlington CDP11.75 sq mi18.0%100.0%
Lexington CDP10.01 sq mi15.4%60.9%
Arlington CDP5.14 sq mi7.9%100.0%
Pinehurst CDP3.73 sq mi5.7%100.0%

Showing all 5 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 5109,96661.6%14.1%42.7%
MA District 644,72125.1%5.7%32.0%
MA District 323,77513.3%3.0%25.3%

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

Voters

Registered Voters
130,691
Active Voters
106,389 (81.4%)

Party Registration

PartyVotersShare
Democratic34,86426.7%
Republican9,3217.1%
Unaffiliated00.0%
Other parties86,50666.2%
No party recorded00.0%

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202626,612 (20.4%)0 (0.0%)0 (0.0%)
2023–2024100,322 (76.8%)28,733 (22.0%)18,257 (14.0%)
2021–202275,071 (57.4%)23,121 (17.7%)7,155 (5.5%)
2019–202093,362 (71.4%)51,279 (39.2%)10,306 (7.9%)
2017–201870,968 (54.3%)21,310 (16.3%)6,586 (5.0%)
2015–201677,957 (59.6%)32,844 (25.1%)15,058 (11.5%)
2013–201453,181 (40.7%)13,761 (10.5%)2,532 (1.9%)
2011–201265,613 (50.2%)8,739 (6.7%)8,616 (6.6%)

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
179,448 (± 875)
Median Age
43.0
Median Household Income
$147,605 (± $4,723)
High School Graduate or Higher (age 25+)
95.8%
Bachelor's Degree or Higher (age 25+)
59.2%

Population by Age

GroupPeopleShare
Under 1834,80419.4%
18 to 64111,80462.3%
65 and over32,84018.3%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)10,2705.7%
White, not Hispanic128,70271.7%
Black, not Hispanic4,8462.7%
Asian, not Hispanic24,67913.8%
American Indian / Alaska Native, not Hispanic510.0%
Native Hawaiian / Pacific Islander, not Hispanic800.0%
Some other race, not Hispanic1,3460.8%
Two or more races, not Hispanic9,4745.3%

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
163,221
Citizen Voting Age Population (CVAP)
130,396

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic154,75694.8%
Hispanic8,4665.2%
White129,14479.1%
Black3,6702.2%
Asian16,78910.3%
American Indian / Alaska Native720.0%
Native Hawaiian / Pacific Islander790.0%
Two or More Races5320.3%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic124,87495.8%
Hispanic5,5194.2%
White107,31282.3%
Black3,1802.4%
Asian13,36710.3%
American Indian / Alaska Native5960.5%
Native Hawaiian / Pacific Islander810.1%
Two or More Races3970.3%

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