Senate Advances Iran War Powers Resolution 50-47 After Republican Sen. Bill Cassidy Flips, Rebuking Trump for the First Time in Eight Separate Floor Attempts

WASHINGTON — The Senate on Tuesday voted 50 to 47 to discharge a war powers resolution that would force President Donald Trump to halt all U.S. military operations against Iran unless Congress votes to authorize them — the first time in eight attempts that the chamber has cleared the procedural hurdle and a stinging public rebuke of the administration's escalating Iran posture. The resolution, introduced by Sen. Tim Kaine, D-Va., now moves toward a Senate floor debate that Democrats hope will force a roll-call vote on the underlying authorization within the next two weeks.

Four Republicans — Sens. Rand Paul of Kentucky, Susan Collins of Maine, Bill Cassidy of Louisiana and Lisa Murkowski of Alaska — broke with their party to advance the measure. Cassidy's vote was the most surprising, coming just two weeks after he failed to clinch a runoff spot in the Louisiana GOP Senate primary, where Trump had endorsed his opponent. "My constituents are deeply opposed to this war," Kaine told reporters after the tally. "Vote by vote, we are breaking through the Republican wall of silence on the president's illegal use of force," Senate Minority Leader Chuck Schumer said on the chamber floor.

Sen. John Fetterman of Pennsylvania was the only Democrat to oppose discharging the resolution. Republican Sens. John Cornyn of Texas, Tommy Tuberville of Alabama and Thom Tillis of North Carolina were absent — Cornyn and Tuberville were back in their home states attending to their own primary elections, while Tillis was reportedly attending a fundraiser in Charlotte. The narrow three-vote margin reflected a body that has grown increasingly uneasy with the open-ended scope of U.S. strikes against Iranian Revolutionary Guard naval assets in the Strait of Hormuz that began in April.

Kaine's resolution would invoke the 1973 War Powers Act to require Trump to "remove the United States Armed Forces from hostilities within or against Iran" within 30 days unless Congress passes a formal declaration of war or a specific authorization for the use of military force. Senior administration officials told CBS News that Trump would veto the resolution if it reaches his desk and that the White House does not believe Democrats can muster a two-thirds majority to override. White House press secretary Karoline Leavitt called the vote "a partisan stunt that endangers American servicemembers in the Persian Gulf."

The vote came hours after Trump told reporters at the White House that he had been "an hour away" from ordering a third round of strikes on the Iranian port of Bandar Abbas before reversing course at the last minute. Iranian Foreign Minister Abbas Araghchi warned in Tehran that "surprises" awaited the United States if any further attacks were launched, while UN Secretary-General António Guterres in a statement Tuesday afternoon urged "maximum restraint on all sides." The House version of the resolution, sponsored by Rep. Ro Khanna, D-Calif., is expected to receive a floor vote next week.