U.S. Senator Bill Cassidy, with his wife, Dr. Laura Cassidy, at his side, addresses his supporters, agreeing to participate in the Republican Party primary elections on May 16, 2026 in Baton Rouge. Cassidy split from his party three days later to support passage of the war powers resolution on Iran. (Photo: Michael DeMocker/Getty Images)
WASHINGTON – After voting “no” seven times, Sen. Bill Cassidy, R-La., changed his mind and cast the deciding vote in favor of a war powers resolution aimed at stopping President Donald Trump’s war on Iran without congressional authorization.
The vote was 50 to 47Cassidy joined fellow Republican Sens. Lisa Murkowski of Alaska, Susan Collins of Maine and Rand Paul of Kentucky, who previously supported the measure.
The vote marked the first time a war powers resolution on Trump’s Iran conflict gained enough Republican support to advance to floor debate.
Cassidy’s vote in favor of Virginia Democratic Sen. Tim Kaine’s resolution came just three days after his defeat in the Louisiana GOP primary, in which Trump endorsed Republican challenger Julia Letlow, R-La.
In a social media post after the vote, Cassidy wrote: “While I support the administration’s efforts to dismantle Iran’s nuclear program, the White House and Pentagon have left Congress in the dark about Operation Epic Fury. I hear people in Louisiana, including President Trump’s supporters, are concerned about this war.”
“Until the administration provides clarity, no congressional authorization or extension can be warranted,” he continued.
Sense. Thom Tillis, R-N.C., Tommy Tuberville, R-Ala. and John Cornyn, R-Texas, did not vote. Trump on Tuesday approved Cornyn’s primary Senate runoff challenger and state Attorney General Ken Paxton.
Earlier votes were unsuccessful
Attempts to limit Trump’s authority to conduct military action in Iran last week failed on both counts House and Senate — although signs of change among Republicans emerged when Murkowski knocked over support this action for the first time.
Trump’s war on Iran is causing his support to decline as gas prices rise and the operation remains in a stalemate.
New York Times/Siena vote released on Monday showed the president’s approval rating has dropped to a fresh low of 37% in his second term. On Iran, 64% of respondents said Trump made the wrong decision to start the conflict.
Thirteen American soldiers were killed in the war that Trump started alongside Israel on February 28. The newest Pentagon figurines reveal that 406 soldiers were injured during Operation Epic Fury, as the administration characterized the conflict.
According to A report released Monday by the Virginia-based Human Rights Activists in Iran organization, just over 1,700 civilians have been killed since the war began, including 307 children. Thousands more were injured, and the report noted that the numbers “should be understood as minimum values.”
Since the outbreak of the conflict, traffic through the Strait of Hormuz has been suspended, causing prices to soar on global markets for oil, natural gas and fertilizers.
According to AAA, Americans pay an average of $4.53 for a gallon of regular gasoline.
