WA-10 · House

The district, in brief

Washington's 10th district is based in Olympia and stretches to the southern Seattle metropolitan area, including Lakewood and Puyallup. It is on the map first used in 2022 and is not redrawn for 2026; the facts carry no presidential baseline for these lines.

The incumbent is Democrat Marilyn Strickland, re-elected with 58.5% of the vote in 2024, a two-party margin of 17.35 points in the facts, which record her first winning the seat in 2020. The Republican nominee is Chris D. Chung, who ran as a Democrat for insurance commissioner in 2024. In the blanket primary Strickland took 47.3% and Chung 31.4%; Democrats Alex Scheel, a community organizer, and Adam Arafat, a county government official, took 10.3% and 9.4%, and independent Derek Maynes and Union candidate Kurtis Engle were also eliminated. As of March 31, 2026 Strickland had raised $1,161,277 with $802,429 on hand; the text lists no report for Chung.

Every rater listed calls the seat D: Decision Desk HQ (July 14, 2026), the Cook Political Report (February 6, 2025), Inside Elections (March 7, 2025), Sabato's Crystal Ball (August 14, 2025) and Split Ticket (July 28, 2026). The text records no district polls.

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 and the facts have no presidential baseline.; No fundraising report is listed for the Republican nominee Chris D. Chung.; No ratings finer than 'D' are given (no Lean/Likely/Safe).; No district polls appear in the text, and the model's basis says no district polls.; The endorsements section is empty.

Read from the district's section of Wikipedia's state page (CC BY-SA), archived as 77b3209be57f; 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

Marilyn Strickland (Democrat), in this chamber since 2021, 3 terms. Committees: House Committee on Transportation and Infrastructure; House Committee on Armed Services.

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 3.4 points toward the Democrats 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 518,911 adults 25 and over. In 2020 the district voted 59.0% Democratic (two-party) for president. With the same preferences and a 2022-style midterm turnout, it would vote 59.2% Democratic: the midterm electorate alone moves the margin 0.4 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 July 15, 2026; $391,142 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 +13.6 to +41.2 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+20.2): 15.4 pts toward the Democrat; 2024 House lean (D+20.1): 8.5 pts toward the Democrat; PAC money balance: 7.4 pts toward the Democrat; experience gap (+4 levels, D minus R): 3.8 pts toward the Democrat; Democrat's experience (incumbent): 1.3 pts toward the Republican.

How sure is it, and of what?

Total sd 8.37 points, made of the seat's own volatility 90%, correlated polling error 10%. 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 0b33151b-a949-47f1-b845-564833a2b74d, 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).