US Senator Bill Cassidy addresses with his wife Dr. Laura Cassidy by his side to his supporters as he leaves his Republican primary campaign in Baton Rouge on May 16, 2026. Cassidy split from his party three days later to support advancing a War Powers Resolution on Iran. (Photo by Michael DeMocker/Getty Images)
WASHINGTON – After voting “no” seven times, Sen. Bill Cassidy, R-La., reversed course and cast the tie-breaking vote to advance a War Powers Resolution to curb President Donald Trump’s war in Iran without congressional authorization.
In a vote of 50 to 47Cassidy joined fellow Republican senators Lisa Murkowski, R-Alaska, Susan Collins, R-Maine, and Rand Paul, R-Ky. who had previously supported the measure.
The vote marks the first time that a War Powers resolution on Trump’s Iran conflict has received enough Republican support to advance to a floor debate.
Cassidy’s vote to advance Virginia Democratic Sen. Tim Kaine’s resolution came just three days after a defeat in the Louisiana GOP primary, in which Trump supported challenger Julia Letlow, R-La.
In a social media post after the vote, Cassidy said: “While I support the administration’s efforts to dismantle Iran’s nuclear program, the White House and Pentagon have kept Congress in the dark about Operation Epic Fury. In Louisiana, I have heard from people, including President Trump’s supporters, who are concerned about this war.”
“Unless the administration provides clarity, no authorization or extension by Congress can be justified,” he continued.
Sens. Thom Tillis, R-N.C., Tommy Tuberville, R-Ala., and John Cornyn, R-Texas, did not vote. Earlier on Tuesday, Trump approved Cornyn’s primary challenger in the Senate runoff and Attorney General Ken Paxton.
Previous votes failed
Attempts to limit Trump’s authority over military actions in Iran failed last week in both Iran and Iran House and Senate — although there were signs of change among Republicans with Murkowski turned around to support the measure for the first time.
Trump’s war in Iran is causing his approval ratings to plummet as gas prices soar and the operation continues to falter.
A New York Times/Siena Opinion poll Polls released Monday showed the president’s approval rating had fallen to a novel low of 37% for his second term. On the Iran issue, 64% of those surveyed said that Trump made the wrong decision in triggering the conflict.
Thirteen American service members have died in the war that Trump started on February 28 alongside Israel. The newest Pentagon Figures reveal that 406 military personnel were injured during Operation Epic Fury, as the government calls the conflict.
According to a report As reported on Monday by the Virginia-based organization Human Rights Activists in Iran, just over 1,700 civilians, including 307 children, have been killed since the war began. Thousands more were injured and the report notes that the numbers “should be understood as minimum levels.”
Traffic through the Strait of Hormuz has been choked up since the conflict began, causing price spikes in global oil, natural gas and fertilizer markets.
According to AAA, Americans pay an average of $4.53 for a gallon of regular gasoline.
