UPDATE: Senate advances bill to force Trump withdrawal from Iran war as Republican Sen. Cassidy switches sides post-primary loss, showing GOP fractures despite Trump backing off planned Tuesday strikes to allow negotiations.
The Senate voted 50-47 on Tuesday to advance legislation forcing President Trump to either gain congressional approval for the Iran war or withdraw troops, with Louisiana Sen. Bill Cassidy providing a crucial vote after losing his primary election last week. The vote demonstrates growing Republican unease with the conflict, though enough GOP senators were absent to potentially defeat the measure on final passage. Trump had backed off planned Tuesday strikes to allow negotiations to continue.
Republican Sens. Rand Paul, Susan Collins, and Lisa Murkowski joined Cassidy in supporting the war powers resolution, while most Republicans maintained their opposition. Cassidy, who previously voted against similar measures, said after his primary loss that he was proud of his work to uphold the Constitution and would carefully consider votes on Trump administration priorities. Trump endorsed Cassidy's primary opponent, contributing to his defeat.
The vote reflects Republican concerns about rising gas prices and the fragile ceasefire in a war that began when Trump ordered attacks on Iran in late February. According to AP reporting, the timing of a final vote remains unclear, but the advancing legislation signals that Trump's Iran policy is hitting significant resistance even within his own party as the conflict grips the Strait of Hormuz.
Editor’s rationale — Senate passage of war powers legislation directly constrains presidential military authority and affects nationwide foreign policy and energy markets; strong AP sourcing and primary institutional action, though final passage uncertain and story is incremental on ongoing debate.