Cassidy says briefing changed his vote on Trump Iran war powers measure

Sen. Bill Cassidy changed his vote on a war powers measure after passing a note to Middle East envoy Steve Witkoff during a heated closed-door lunch with Donald Trump and Senate Republicans in the Capitol. Cassidy said in a CBS News preview of an interview set to air Sunday that he told Witkoff he would consider changing his vote because he had not been briefed. He later received an Iran briefing from Vice President JD Vance and Witkoff at the White House on Wednesday afternoon, and said it addressed many of his concerns.

The note became the backchannel inside a fight that centered on U.S. war powers and Trump’s policy toward Iran. Cassidy’s message to Witkoff read, “Steve, I would consider changing my vote, but I’ve been voting yes because I’ve not been briefed,” a sign that access to information, not just party loyalty, was shaping the decision. The White House briefing came after the confrontation and gave Cassidy the substantive update he had been seeking.

The clash in the Capitol was sharp enough that other senators had to step in. Cassidy, a Louisiana Republican who has been viewed as a possible source of trouble for Trump if he chose to use his leverage, found himself at the center of a dispute over how much authority the president should have over military action in Iran. The episode fit a broader pattern of Trump publicly pressing Republican lawmakers to line up behind his foreign-policy priorities.

The Senate had passed the Democratic-led measure on Tuesday, June 23, 2026, with four Republicans joining Democrats. By late Wednesday, June 24, Republicans reversed course and rejected it after Trump berated senators who had backed the challenge. Cassidy’s switch, after a direct briefing from Vance and Witkoff, showed how quickly the balance can change when the White House makes the cost of dissent plain and gives a wavering senator a reason to move.