NJ-12 · House

The district, in brief

New Jersey's 12th is composed of much of Central Jersey, taking in the state capital Trenton and neighboring Princeton University, along with Plainfield to the north. The lines are the map first used in 2022 and are not redrawn for this cycle. The facts record a 2024 House two-party margin of 25.36 for the Democrat; no presidential baseline is on file.

The seat is open: the incumbent, Democrat Bonnie Watson Coleman, re-elected with 61.2% in 2024, is listed among the withdrawn Democratic candidates. The Democratic nominee is Adam Hamawy, a surgeon, who won a thirteen-name primary with 28.6% over East Brunswick mayor Brad Cohen (14.6%), professor Sam Wang (9.4%), Somerset County commissioner Shanel Robinson (8.9%), state assemblymember Verlina Reynolds-Jackson (8.8%) and Sue Altman (8.5%). Hamawy won none of the three county conventions recorded but led primary fundraising with $1,028,936 raised as of May 13, 2026. The Republican nominee is Gregg Mele, an attorney and perennial candidate, unopposed in his primary. Andres Jinete (Green Party) and Winston Jordan (Get Money Out) are also on the ballot. As of May 13, 2026 Hamawy had $310,697 on hand and Mele had raised $67,518 with $5,182 on hand.

Decision Desk HQ (July 14, 2026), the Cook Political Report (August 13, 2025), Inside Elections (March 7, 2025) and Sabato's Crystal Ball (April 10, 2025) all call the seat D; Silver Bulletin is listed (August 23, 2026) with no ranking shown. The only polls recorded are two Workbench Strategy surveys of the Democratic primary; the later one (May 5–7, 2026) had Hamawy at 19%.

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Not in the source: The text lists Watson Coleman under 'Withdrawn' but gives no date or reason for her retirement.; No presidential result on these lines is given in the text or the facts.; No general-election polls are recorded; the two polls are of the Democratic primary.; The general-election fundraising table repeats the May 13, 2026 figures; no June 30 report is given.; Silver Bulletin appears in the ratings table with no ranking shown, and no rating finer than 'D' is given.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as 40017e08a73c; 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

Bonnie Watson Coleman (Democrat), in this chamber since 2015, 6 terms. Committees: House Committee on Appropriations; House Committee on the Budget.

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 8.2 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 530,209 adults 25 and over. In 2020 the district voted 67.3% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 66.7% Democratic: the midterm electorate alone moves the margin 1.4 points toward Republicans. 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 31, 2026; $2,936,503 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 +9.6 to +39.1 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+26.0): 16.6 pts toward the Democrat; PAC money balance: 8.1 pts toward the Democrat; 2024 House lean (D+28.1): 4.7 pts toward the Democrat; total outside/party money: 1.4 pts toward the Republican; foreign born share (32.0%): 1.4 pts toward the Republican.

How sure is it, and of what?

Total sd 8.96 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 6f211e6f-2bdc-4dda-8f72-81fc628dab0b, 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).