By Lindsay Wise

WASHINGTON -- Just days after President Trump celebrated ousting incumbent Republican Sen. Bill Cassidy in Louisiana's GOP primary election, Cassidy voted in favor of advancing a resolution that would limit Trump's ability to wage war in Iran without congressional approval.

The procedural vote, which passed 50-47, marked the first time Cassidy had supported such a resolution since Trump launched the war against Iran in February. The senator hadn't supported similar measures in seven previous votes, when he was still in the throes of his re-election campaign.

Senate Republicans had managed to quash each of those Iran war powers resolutions until Tuesday, when three absences among Republican senators enabled one to advance.

On Tuesday, Cassidy joined GOP Sens. Lisa Murkowski of Alaska, Susan Collins of Maine and Rand Paul of Kentucky in backing the measure. All Democrats voted in favor of the measure except for Sen. John Fetterman of Pennsylvania. Three Republicans were absent.

Leaving the Senate floor after his vote, Cassidy didn't respond to reporters' questions, saying he would post a statement later on social media.

Senate Minority Leader Chuck Schumer (D., N.Y.) said Republicans are starting to crack, and momentum is on Democrats' side.

"Vote by vote, Democrats are breaking through the Republican wall of silence on Trump's illegal war," Schumer said. "It's now 80 days. Trump has dragged us into a costly war with no end in sight, that's costing Americans not only at the gas pump but in many other ways."

A Senate GOP leadership aide said the resolution won't advance any further because Republicans will have the votes to defeat it when the absent senators return.

But Sen. Tim Kaine (D., Va.), who sponsored Tuesday's resolution, said ahead of the vote that advancing the measure would signal the "ice is melting" among Republicans. "What changes the equation here is what people hear from their constituents" back at home who are facing higher prices at the pump heading into the Memorial Day weekend.

Republicans have narrow majorities in the House and Senate. War-powers resolutions in both chambers have inched closer to passing in recent days, as small numbers of Republicans break with Trump and their party, voting to direct the president to remove U.S. troops from hostilities against Iran, or seek authorization from Congress. A vote in the House on an Iran war-powers resolution last week ended in a 212-212 tie.

Trump has largely ignored Congress in his overseas military strikes. Several weeks ago, Trump notified Congress that hostilities against Iran ended in April, allowing the White House to bypass a 60-day deadline for lawmakers to approve the war. The White House maintained that the U.S. ceased combat operations against Iran when the two countries agreed to a temporary cease-fire on April 7 that has since been extended. Trump could veto any war-powers measure.

Write to Lindsay Wise at lindsay.wise@wsj.com

(END) Dow Jones Newswires

May 19, 2026 18:36 ET (22:36 GMT)

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