2026 ballot measure forecast

Washington Initiative Measure No. IL26-638

Girls' sports limited to biological females

Bars students defined as biologically male from girls' interschool sports and requires a provider statement verifying sex to participate. The forecast has Yes at 54.0 percent against the 50 percent it needs, a 73% chance to pass.

Leans passCitizen initiated statuteTransgender policy and marriageUpdated October 17, 2026

Chance to pass

73%

2,000 simulations

Forecast Yes

54.0%

80% range 45 to 63

Needs

50%

a simple majority

Polling average

58.1%

Yes, with undecided split two to one for No

County forecast

36 of 39 counties vote Yes

No +30Yes +30Hover a county for its forecast

Where the Yes vote lands

needs 50

2035506580

History and structure: 48.6% Yes
Polls: 58.1% Yes
Forecast: 54.0% Yes
Yes leans: Republican
Rule to pass: Simple majority of votes cast on the measure.

The campaign

Let's Go Washington (Brian Heywood) initiative to the Legislature, 400,000 plus signatures; Legislature did not act; WEA and Northwest Progressive Institute oppose.

Also on the Washington ballot

Initiative Measure No. IL26-001

Parents' Bill of Rights reinstatement

31%

Initiative Measure No. IP26-645

Repeal millionaires income tax, ban income taxes

11%

Polls of the measure

1 poll

Pollster	Sample	Ended	Yes	No	Undecided	Yes, adjusted
Undisclosed · for the Yes side	7,500 LV	2026-08-31	56	24	22	58.1%

How this is built

Initiative Measure No. IL26-638 is forecast as a transgender policy and marriage measure whose Yes vote leans Republican. Comparable measures from 2018 to 2024 set how far its Yes share moves with Washington's partisanship and with each county's 2024 presidential vote, and how it reached the ballot moves it further. Polls then pull the forecast toward them by recency and size, after splitting undecided voters two to one for No. Sources: theurbanist.org , kxly.com , en.wikipedia.org , kuow.org. All measures.