Sen. Bill Cassidy, who lost his primary this weekend, became the latest GOP defector as critics took advantage of Republican absences to advance a war powers resolution.
The letter to lawmakers attempts to justify why the president is not seeking congressional authorization after the conflict reaches a 60-day threshold.
The Middle East conflict faces a ticking war powers clock for lawmakers to authorize continued operations that could be a bigger political headache for Trump and Republicans.
The House Armed Services Committee chair said the department owes lawmakers more information about the administration’s plans for U.S. troops in the Middle East.
This was the third test of GOP support for the president's actions, even as oil prices have shot up and the American public appears increasingly disenchanted with the war.
The ballooning cost of the war is certain to intensify an already toxic fight on Capitol Hill over the Trump administration's three-week military campaign in the Middle East.
Lawmakers will effectively be spectators in the president’s decisions around the Iran war after both the House and Senate rejected efforts to curb Trump’s power.
The Arizona Democrat and five other lawmakers with military or intelligence backgrounds have been attacked by the president over a video they released in November reminding military personnel not to follow illegal directives.
GOP lawmakers pulled out all the stops to manage a tie vote and keep a war powers effort at bay a week after Senate Republicans quashed a similar measure.
The procedural vote is a rare critique of Trump’s authority in the first test of GOP loyalty since last weekend’s capture of Venezuelan President Nicolás Maduro.
"We’ve entered the 250th year of American democracy and cannot allow it to devolve into the tyranny that our founders fought to escape,” Sen. Tim Kaine said.