MA-6 · House

The district, in brief

Massachusetts's 6th district represents northeastern Massachusetts and includes Salem, Peabody and Gloucester; the map in force was first used in 2022 and was not redrawn for this cycle. The text gives no presidential result for the district.

The seat is open. Democratic incumbent Seth Moulton, re-elected uncontested in 2024, declared on October 15 for U.S. Senate against Ed Markey after his comments on transgender individuals drew condemnation from Democrats including Governor Maura Healey. The Democratic nominee is Dan Koh, a former deputy director of the White House Office of Intergovernmental Affairs and former Andover selectman who ran for the 3rd district in 2018; he won the primary with 40.9% (47,835 votes) over state representative Tram Nguyen (29.4%), self-funder John Beccia (12.2%) and Jamie Belsito (9.6%). As of August 12, 2026 Koh had raised $4,716,543 with $1,994,307 on hand; Beccia raised $4,513,050, of which $3,043,664 was self-funded. The Republican nominee is Micah Jones, an attorney and U.S. Army veteran, who took 99.2% in his primary and had raised $400,168 with $250,856 on hand as of June 30, 2026.

Every rater that gives a call lists the seat as D: Decision Desk HQ (July 14, 2026), the Cook Political Report (February 6, 2025), Inside Elections (March 7, 2025) and Sabato's Crystal Ball (July 15, 2025); Silver Bulletin appears with a date of August 20, 2026 but no rating. The only district polls in the text are Democratic primary polls; the latest, Global Strategy Group (D) on August 20–23, 2026, had Koh 35%, Nguyen 20%.

A paragraph quoting a model forecast from the day this brief was written is omitted; the current forecast is at the top of this page.

The facts, each beside its sentence

Not in the source: The text gives no presidential result for the district in any year.; The year of Moulton's October 15 Senate announcement is not stated in the text.; No general-election ratings finer than 'D' are given, and the Silver Bulletin row carries a date but no rating.; All district polls are Democratic primary polls; no general-election poll appears, and the model's basis is prior only.; No fundraising figures later than June 30, 2026 are given for Jones.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as 68305940acd8; written by claude-fable-5-1 (batch reader) on 2026-09-30 and checked mechanically: every quote occurs verbatim in the archived text, every number in the brief occurs in the inputs. No probability here is the reader's.

Who holds the seat now

Seth Moulton (Democrat), in this chamber since 2015, 6 terms. Committees: House Committee on Transportation and Infrastructure; House Committee on Armed Services; House Select Committee on the Strategic Competition Between the United States and the Chinese Communist Party.

From the congress-legislators dataset (CC0), archived as ae8cb9477c48. For a Senate race this lists both of the state's senators; the one whose term ends in the election year holds the seat on the ballot. For a House district redrawn for 2026 it is the member elected under the old lines with this number, who may be running elsewhere; the dossier above names who is running here.

How it has voted for president

A shift of 2.6 points toward the Republicans from 2016 to 2024. county returns placed on the current lines by 2020 block population; MEDSL county file (2016), an MIT-licensed county file (2020, checked against certified state results) and MEDSL precinct returns (2024). For a district split across counties this is an estimate, and where the state published the exact 2024 figure for these lines, that exact figure is the one the model uses.

Who are the voters?

Of about 556,450 adults 25 and over. In 2020 the district voted 64.1% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 65.5% Democratic: the midterm electorate alone moves the margin 2.7 points toward Democrats. Group shares are estimated from how results vary across the state's census tracts (ecological inference, anchored to Pew's 2020 validated-voter figures) and calibrated to this district's actual 2020 vote; turnout is the Census survey's state rate by race and national rate by education, whose state samples carry margins of several points.

Not answered here: how each group will vote in 2026. These are 2020 preferences; this profile is description, not yet an input to the forecast.

The money

FEC bulk candidate summaries through August 12, 2026; $2,260,624 of independent expenditures for or against these candidates this cycle (FEC Schedule E, types 24E and 24A), which is the parties' and outside groups' own revealed view of whether this seat is in play.

The district in numbers

ACS 5-year 2023, the Census Bureau's own tabulation of this district (118th Congress lines). Unemployment is the BLS county series placed on the district by block population, not seasonally adjusted, so changes are same-month comparisons. Income, transfers and jobs are BEA county accounts placed the same way, compared with the average district. Every other figure is a named column of a named table in the Bureau's summary file, archived before it was read. This is what a reader knows about a district before looking at a poll; the model does not yet use it, and whether it should is a registered question.

Who is favoured, and by how much?

The 90% interval runs from +21.5 to +51.1 points, D-R. It is wide because this district has never been polled.

What is this built on?

A model trained on every contested House race 2012-2024 predicts this district's lean from its own record: presidential and House results on the current lines, incumbency, both candidates' prior offices, outside and party money before 1 October, demographics and public-assistance shares from the Census release before the election, local unemployment and income, and religious tradition. The national margin comes from presidential approval, the economy, the midterm penalty and the generic ballot corrected for its measured lean. Draws share national and state errors, so the seat total and this district come from the same simulation.

Not answered here: district polls, which are not yet folded in.

Why does the model say this?

Each figure is how far this district's predicted lean moves when that one feature is set to the typical value across 2026 districts, everything else held: 2024 presidential lean (D+22.6): 22.4 pts toward the Democrat; 2024 House lean: 9.9 pts toward the Democrat; PAC money balance: 9.1 pts toward the Democrat; experience gap (+1 levels, D minus R): 8.6 pts toward the Democrat; 2022 House lean (D+30.7): 1.3 pts toward the Democrat.

How sure is it, and of what?

Total sd 9.00 points, made of the seat's own volatility 91%, correlated polling error 9%. The decomposition is stored with the forecast rather than reconstructed, so a probability whose dominant input is a placeholder is visibly that.

Not answered here: a nowcast. 'If ballots were cast today' needs something that observes today, and for a House district nothing does. Publishing the election-day figure under both labels would make one forecast look like two.

How was this number made?

Run 00a09d4b-7980-4ec5-ada0-077968a87242, house_district_prior/0.2.0, as of 2026-10-02. Promoted by a pre-registered gate: on 2016-2022 its Brier score was 0.036 against 0.049 for the previous method, and on a single 2024 run 0.023 against 0.032 (experiments/district_gate_result.md, with an independent review).