S. 638 — A bill to amend the Act of June 22, 1948.

4%becomes law moderate confidencepending: Senate on_calendar

Amend the Act of June 22, 1948. — on the calendar, quiet for 222 days; 10% to reach the floor, 4% to become law.

10%

reaches a floor vote

99%

passes if voted (stage model)

34%

survives downstream

becomes law

The gap: on the floor this would pass — 45% by the member-vote simulation — but the floor is the hard part: 10% to ever get the vote. That gap, not the whip count, is the story.

If it reaches the floor

majority

60 (cloture)

Projected 62 yea of 100 voting; 90% interval 32–94 (quartiles 51–76). Intervals are backtest-verified to cover ~90%.

Filibusterable: the realistic Senate line is 60 votes — P(≥60) = 45% (simple-majority P = 81%).

By floor procedure

No vote is scheduled, so the headline marginalizes over how the Senate would take it up; the branches:

Procedure	Likelihood	Projected yea	Passes
conference	5%	67 [42–95]	88%
passage	95%	61 [31–94]	80%

Receipts

Sponsor: Tina Smith (D). Latest action (2025-10-27): Placed on Senate Legislative Calendar under General Orders. Calendar No. 208.
Full record: Congress.gov.

Forecast run predict-20260606T193507Z · models member-vote-1.0.0-t117d118-20260606 + passage-1.0.0-t117d118-20260606 · conditional whip forecasts for the Senate run at moderate confidence (why).