WASHINGTON―A Senate resolution to block President Trump from further escalating hostilities with Iran faced an uphill battle Tuesday, as key Republicans had yet to commit their support.

Since the U.S. strike that killed Iran Quds Force commander Qassem Soleimani last week, Democrats have been seeking to reassert Congress’s authority to block what they fear will lead to another costly, bloody war in the Middle East. One avenue is a privileged resolution from Sen. Tim Kaine, D-Va., who attracted four Republicans to a similar measure in June.

The House and Senate will both consider resolutions asserting that Trump cannot use existing war authorizations for a legal basis to fight Iran. Kaine’s resolution is co-sponsored by the Senate Minority Whip Dick Durbin, D-Ill., in the Senate, and a corresponding resolution sponsored by Rep. Elissa Slotkin, D-Mich., is set to be considered by the House.

For procedural reasons, the Senate resolution is not expected to come to the floor until at least Jan. 14, according to Kaine. The House resolution is expected to come up for a debate and vote this week.

“We’re spending time to try to get votes, and we’re going to have a vote. Everybody’s got to declare,” Kaine said. “I don’t know what the total will be, but I believe from earlier votes there are people who believe in the congressional imperative, that whatever they think of war with Iran that it should be Congress that should decide it rather than the president on his own.”

The Senate resolution would require the withdrawal of any added armed forces from “hostilities” toward Iran within 30 days of its passage, and it emphasizes that the 2002 war authorization used to fight Saddam Hussein’s Iraq does not apply to any action the administration might intend to take against Tehran.

Though the resolutions put pressure on Republicans, top GOP leaders, such as Senate Majority Leader Mitch McConnell, have been messaging about the longstanding threat posed by Iran. Trump acted decisively, McConnell said Tuesday, “to remove the chief architect of Tehran’s terrorism from the battlefield.”

Senate Armed Services Committee Chairman Jim Inhofe, R-Okla., called the strike Trump’s “boldest defensive policy decision to date ... in accordance with his authorities as commander-in-chief,” per the U.S. Constitution’s Article II. The strike, Inhofe said, was “not war.

“Nobody here wants war, but at the same time nobody should want a policy that would leave Americans vulnerable to the whims of Iran's terrorist-supporting regime,” Inhofe said. “If we do that, if we tie the president's hands so that he cannot defend American lives, we leave ourselves more vulnerable and, therefore, make war infinitely more likely.”

On Tuesday, three of the Republicans who supported Kaine’s previous action were not yet aboard. Asked if he was taking the resolution seriously, Sen. Mike Lee, R-Utah, expressed his opposition.

“Not as written, no,” Lee said. “A lot of the findings of fact [stated in the resolution] really overstate things.”

Lee was among Republican “yeas” when Kaine introduced a since-failed amendment to the 2020 defense policy bill that would have barred the U.S. from entering hostilities with Iran unless Congress approved it. The final vote tally was 50-40, but the amendment was not adopted because it did not meet the required 60-vote threshold―much less a veto-proof majority.

Of the Republicans who broke with Trump and joined the Democratic minority then, Sen. Susan Collins, of Maine; Sen. Jerry Moran, of Kansas, and Sen. Rand Paul, of Kentucky, have each said they were still considering their positions. Kaine said he was lobbying Republicans and was not immediately sure how many would join him.

“I want to hear more about it,” Moran told reporters Tuesday.

“I want to see the specific language of it,” Collins said. “In general, I believe Congress has abdicated its responsibilities over the last decade when it comes to [war powers] and the commitment of military troops, but obviously there was to be an exception for when the United States is facing an imminent threat.”

Paul told CNN on Monday he was leaning in favor but still examining the resolution, despite the administration’s assertions it was acting to protect against an imminent threat.

“I, in general, have always supported that a declaration of war is necessary,” Paul said. “I think killing a country’s major general is an act of war. I don’t think you can get away with saying it’s imminent. They have been complaining for years about Soleimani."

Kaine has other possible Republican allies. Sen. Todd Young, of Indiana, introduced a bill with Kaine in March to repeal the 2002 war authorization against Iraq; Young was noncommittal Tuesday morning.

“I don’t know yet,” Young said of Kaine’s resolution. “I’m visiting with Sen. Kaine today to dive into some of the details and talk through them with him."

The effort to check Trump has other obstacles. Even if a war powers resolution were to pass Congress, it could be vetoed by the president or, as is typical, contain a carve-out to allow a military response to an imminent threat, Sen. Chris Murphy, D-Conn., acknowledged.

“But I think we have no choice to force a debate on the Senate floor, if only to force Republicans to come up with some answers for why they’re not prepared to engage in any more robust checks on this president’s reckless Iran policy,” said Murphy, who is the top Democrat on the U.S. Senate Foreign Relations Subcommittee on Near East, South Asia, Central Asia and Counterterrorism.

“I think there is value in forcing a debate for the purposes of educating the public. If we don’t use the Senate floor to have debate about Trump’s bizarre and nonsensical Iran policy, we’re not doing our job.”

Joe Gould is the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He served previously as Congress reporter.

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