The War Powers resolution, which passed by a vote of 224 to 194, limits Trump’s ability to go to war with Iran without first seeking congressional approval. And while the measure does not require a presidential signature, it comes amid what critics contend has been a decades-long abdication of Congress’ authority to declare war.

“We owe it to our military and to ourselves as a nation to open this conversation of the authorization of military force, to provide our troops that clarity and to abide by the Constitution that we have all sworn to protect,” said Rep. Elissa Slotkin (D-Mich.), a former CIA analyst and the lead sponsor of the bill.

Republicans argued the resolution was dangerous and would send the wrong message at a time of increasing tensions between the U.S. and Iran, and would inappropriately hamstring the commander-in-chief.

“It will not become law, but it will embolden Iran,” said Rep. Liz Cheney (R-Wyo.), the third-ranking Republican in the House.

Eight Democratic centrists opposed the resolution, in part because they believe the measure was brought to the floor too quickly with uncertainty still high in the region, according to several people familiar with the concerns.

“This threat is evolving quickly, and at this point I’m not willing to restrict the U.S.’s ability to respond to keep us safe,” Rep. Stephanie Murphy (D-Fla.), who previously worked on national security issues at the Pentagon, said in an interview. “We need to have the capability to respond.”

Another moderate, Rep. Max Rose (D-N.Y.), said he would oppose the measure for procedural reasons, arguing that the measure is effectively toothless in forcing Trump’s hand.

“Unfortunately, today’s War Powers resolution is a non-binding resolution that simply restates existing law and sends the message that war is imminent,” Rose said. “I refuse to play politics with questions of war and peace and therefore will not support this resolution.”

Despite a public plea from Trump earlier in the day for his party to remain in line, three Republicans voted for the War Powers resolution — a measure that Congress has used sparingly in history but has been approved twice in the House since Trump became president, both related to the civil war in Yemen.

Democrats said they worked tirelessly to ensure that at least a few Republicans backed the measure. One of those Republicans, Rep. Matt Gaetz of Florida, successfully stripped the resolution of language that condemned the strike on Soleimani. While Gaetz is a close ally of the president, he has long held anti-war tendencies.

“I support the president, killing Soleimani was the right decision, but engaging in another forever-war in the Middle East would be the wrong decision,” Gaetz said on the House floor.

Democrats — in particular the caucus’ large group of members with experience in the national security field — said it was important for the legislative branch to re-assert its authority over the power to go to war.

“This is a critical decision and a critical responsibility of Congress, and I think people are certainly taking the responsibility of voting for or against this very seriously,” Rep. Mikie Sherrill (D-N.J.), a former Navy helicopter pilot, said about the vote.

“Personally, as I said, I think it's critical that Congress weigh in on these issues. And I think Congress has abdicated its responsibility in several ways over the years and it's important that we don't do so now,” Sherrill added.

The politics of the war powers vote have fluctuated dramatically over the past week, with lawmakers watching in horror as Iran launched a retaliatory strike on Tuesday night but later breathing a sigh of relief when Trump himself used a presidential speech on Wednesday to cool tensions in the region.

The vote is a major win for progressive Democrats, including prominent anti-war advocate Rep. Barbara Lee (D-Calif.), who has pushed for decades to constrain what she sees as limitless executive power to wage war across the globe.

The measure will now head to the Senate, where several more Republicans are expected to break with Trump in a vote expected as early as next week.

A similar resolution from Sen. Tim Kaine (D-Va.) already has support from GOP Sens. Mike Lee of Utah and Rand Paul of Kentucky, but Kaine will need at least two more Republicans to back the resolution for it to pass the Senate.

The War Powers Resolution is unlikely to rein in the White House’s use of force, however. Republicans criticized the Democratic-led effort as toothless, noting that it is non-binding and therefore will not reach the president’s desk.

Tensions between Washington and Tehran ramped up significantly last week when Trump ordered a strike against Soleimani, a powerful figure in the country who commanded its elite Quds Force.

The airstrike, which killed Soleimani and prompted an angry response from the Islamist regime, drew widespread condemnation from Democrats, who called Trump’s decision impulsive and said it had the potential to unleash an all-out war. Democrats also questioned the legality of the strike, which was conducted without congressional authorization, and they disputed the Trump administration’s claims that there was an “imminent” threat posed by Soleimani.

“It wasn’t clear to me that they had specifics about what that imminent threat was,” House Armed Services Committee Chairman Adam Smith (D-Wash.) told reporters.

Iran retaliated for the killing of Soleimani earlier this week by striking two Iraqi bases housing U.S. troops, but the soldiers received advanced notice of the attacks and were able to take cover. No Americans were killed in the strikes. Trump addressed the nation a day later, confirming that Iran was standing down and appearing to de-escalate.

Senior Trump administration officials briefed House members and senators on Wednesday about the situation with Iran. Democrats described the briefings as “sophomoric” and insufficient. Lee (R-Utah) said it was one of the worst military briefings he had ever received, and it prompted him to support the Senate companion to the House’s War Powers resolution.

Several lawmakers said the briefings — led by Secretary of State Mike Pompeo, Defense Secretary Mark Esper, and CIA Director Gina Haspel — failed to make a persuasive case that Soleimani presented an imminent threat to Americans.

Lee and other lawmakers also said the officials warned that Congress should not even debate War Powers legislation or any other measures that would restrict Trump’s authority to attack Iran. Lee said their comments were “un-American” and “unconstitutional.”

For the most part, Republicans backed the president’s decision to take out Soleimani and said they were satisfied with the briefing. They commended Trump for showing restraint after Iran’s retaliatory strikes earlier this week.

Trump hosted top congressional Republicans for lunch at the White House on Thursday to discuss Iran, according to a source familiar with the matter. Attendees included Senate Intelligence Committee Chairman Richard Burr (R-N.C.), Senate Foreign Relations Committee Chairman Jim Risch (R-Idaho), House Armed Services Committee Ranking Member Mac Thornberry (R-Texas), House Foreign Affairs Committee Ranking Member Michael McCaul (R-Texas) and House Intelligence Committee Ranking Member Devin Nunes (R-Calif.).

In the Senate, Kaine and his fellow Democrats are actively working to convince more GOP senators to back the measure.

Among the undecided Republican senators is Todd Young of Indiana, who acknowledged Thursday that the Trump administration’s briefing could have been more thorough.

“The legal analysis behind this strike — that analysis could have been more rigorous,” Young said. “It would have been a lot more helpful had I gotten a little peek into some of the intel that informed the operational decisions.”

Sen. Susan Collins (R-Maine), who is viewed as another potential Republican vote and met with Kaine about the resolution Wednesday, said on Thursday that “Congress for decades has abdicated its responsibility in the area of the War Powers Act.”

But she added that she does not “want to send a signal to Iraq, or to Iran rather, that America is divided on the strike,” and said she has concerns about the timing and the scope of Kaine’s proposal.

Connor O’Brien, John Bresnahan and Marianne LeVine contributed to this report.

