PA-1 · House

The district, in brief

Pennsylvania's 1st district is based in the northern suburbs of Philadelphia, including all of Bucks County and parts of Montgomery County. The lines are unchanged for 2026 (map first used in 2022).

The incumbent is Republican Brian Fitzpatrick, re-elected with 56.4% of the vote in 2024. The text describes him as a moderate expected to face a primary challenge from the right after voting against the One Big Beautiful Bill Act; none came, and Mark Houck, the 2024 candidate, declined. The Democratic nominee is Bob Harvie, chair of the Bucks County Commission since 2020, who won the Democratic primary with 65.1% over Lucia Simonelli, a mathematician. As of June 30, 2026 Fitzpatrick had raised $6,734,931 with $6,355,534 on hand; Harvie had raised $2,007,499 with $794,921 on hand.

Four raters call the seat R: Decision Desk HQ (July 14, 2026), the Cook Political Report (October 22, 2025), Inside Elections (December 5, 2025) and Sabato's Crystal Ball (October 22, 2025); Silver Bulletin calls it Tossup (August 20, 2026). Five district polls are recorded. Public Opinion Strategies, a Republican firm polling for Fitzpatrick's campaign (September 11–14, 2026), had Fitzpatrick 49%, Harvie 40%. Democratic firms had it closer: GQR (August 19–23, 2026) 49%–48%, Global Strategy Group 47%–43% (August 5–9, 2026) and 48%–42% (March 19–22, 2026), and Public Policy Polling, for Harvie's campaign (October 10–11, 2025), tied at 41%.

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 results for the district; the facts carry a 2024 presidential baseline on the current lines.; The model's basis says no district polls, but the text carries five polls that are not in the project's poll corpus.; The endorsements and post-primary endorsements sections are empty.; The text does not name the 2024 Democratic nominee.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as 716a870fb99d; 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

Brian K. Fitzpatrick (Republican), in this chamber since 2017, 5 terms. Committees: House Committee on Ways and Means; House Permanent Select Committee on Intelligence.

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 0.6 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 547,313 adults 25 and over. In 2020 the district voted 52.3% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 53.7% Democratic: the midterm electorate alone moves the margin 2.8 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 June 30, 2026; $33,445 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 -15.4 to +12.9 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: experience gap (-3 levels, D minus R): 5.6 pts toward the Republican; total outside/party money: 3.1 pts toward the Democrat; 2024 House lean (R+10.1): 2.8 pts toward the Republican; PAC money balance: 0.7 pts toward the Republican; outside money balance: 0.6 pts toward the Democrat.

How sure is it, and of what?

Total sd 8.62 points, made of the seat's own volatility 89%, correlated polling error 11%. 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).