99chambers

U.S. House seat · lines in effect since 2022

Massachusetts's 9th District

A district of about 791,000 people, 43% of adults with a bachelor's degree. It votes D+12.8 relative to the nation for president.

William R. Keating (D) · since Jan 5, 2011Next election Nov 7, 2028The 2026 race →
MA-9

Source: 2026 results: civicAPI; boundaries: Census Bureau TIGER/LineUpdated Nov 7, 2026, 3:01 PM ET

Where it sits among all 435 seats

Every U.S. House seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.

D+12.8151st most
Democratic
Most DemocraticMost Republican218th seat · the majority line75826431MA-9

Labels below the bar mark 8 other seats in Massachusetts.

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

Every race on these lines

Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.

202220242026
U.S. HouseD+18.4D+13.0D+21.7

Outlined: the race for this seat itselfBlank: no race that year

Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 7, 2026, 3:01 PM ET

Who lives here, compared

Grey bars show the spread of all 435 seats. Small marks are other seats in Massachusetts. The black marker is MA-9.

Adults with a bachelor's degree43% 77th pct · 7th of 9 in MA

Higher than 77% of seats.

White adults without a degree47% 71st pct · 2nd of 9 in MA

Higher than 71% of seats.

Hispanic residents6% 22nd pct · 9th of 9 in MA

Lower than 78% of seats.

Black residents2% 18th pct · 9th of 9 in MA

Lower than 82% of seats.

Asian residents1% 17th pct · 9th of 9 in MA

Lower than 83% of seats.

People per square mile241 45th pct · 9th of 9 in MA

Less dense than 55% 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.

CT-2
40% college gradsD+8.9Held DOR-5
39% college gradsD+8.6Held DNH-1
42% college gradsD+3.0Held DME-1
44% college gradsD+22.6Held 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.

  1. William R. Keating (D)
    2023– · Won 2022 by 18.4, 2024 by 13.0, 2026 by 21.7

Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)