Senator Lisa Murkowski's Iran AUMF draft has not formally reached committee, but Susan Collins and Thom Tillis publicly signalled support on 25 April 1. Tillis told reporters he has been "in conversations with Murkowski about her proposal" and said it "would put to bed this whole narrative about whether Congress supports ongoing action". John Curtis of Utah signalled similar reservations about war authority. Josh Hawley's earlier AUMF push has gone quiet.
The Authorisation for the Use of Military Force is the formal congressional instrument that licenses the executive branch to keep US forces in hostilities. Without it, the War Powers Resolution of 1973 imposes a 60-day clock from the introduction of US armed forces into hostilities; the Senate rejected the fifth WPR by 51-46 on 22 April and Murkowski drafted the AUMF in the same week . If the vehicle reaches markup before 1 May it creates a bipartisan signed instrument the executive branch does not control, potentially binding operational authorities the President has so far exercised verbally.
Senate Democrats hold a further eight WPR resolutions in procedural reserve, which extends pressure into May regardless of what Murkowski produces by Friday 1 May. The exact start date for the WPR clock is contested, with 28 February (first CENTCOM engagement), 4 March (first confirmed hostile fire exchange), or a later date The Administration may argue. If the trigger date is challenged before the courts, the 1 May deadline could be extended without a Senate vote.
