With Senator Rand Paul’s decision to support a resolution to block President Trump’s emergency declaration, Congress appears ready to deliver a stern rebuke to the president over his border wall and a clear statement that it will defend its ability to control federal spending.
Senator Paul, a libertarian-minded Kentuckian, said he will join fellow Republican Senators Susan Collins of Maine, Lisa Murkowski of Alaska and Thom Tillis of North Carolina, giving proponents of the resolution of disapproval the 51 votes they need, if Democrats remain united in their support.
On Monday, Senator Mitch McConnell of Kentucky, the majority leader, confirmed that the measure has the votes to pass the Senate. Senate leadership, he said, has been conferring with the Senate parliamentarian to see if the House-passed resolution could be amended before the vote.
“It’s an interesting question,” Mr. McConnell said at a news conference in Kentucky. “It’s never been done before.”
The measure, outlined in the National Emergencies Act, is the simplest way for Congress to end a president’s national emergency declaration. Mr. Trump has said he will veto it, and neither chamber is likely to muster the two-thirds majority needed to overturn the veto. But the plaintiffs in multiple lawsuits will most likely seize upon a congressional repudiation as support for their argument that, in declaring a national emergency to take money for his wall that was not appropriated by Congress, Mr. Trump is subverting the Constitution, which grants Congress clear control over federal spending.
The remaining question: How stern a rebuke will the Senate deliver?
Here’s what to watch for as more Republican senators prepare to announce how they will vote on the resolution.
The Pragmatists: Not from my backyard.
Mr. Trump is hoping to divert $3.6 billion from military construction projects to his cherished wall at the southwestern border, effectively subverting lawmakers and the budget they set.
Members of the Senate Appropriations Committee, who pride themselves on bipartisanship, have raised concern that Mr. Trump is taking funds that were carefully doled out after months of negotiation in the bill that he signed last month to fund the government through Sept. 30. His declaration marks the first time the National Emergency Act has been invoked because Congress has denied the president funds.
Senator Lamar Alexander, Republican of Tennessee, said the president should use funds already approved by Congress, for instance from Defense Department accounts to support interdiction of illegal drugs.
“It avoids taking money for military construction projects specifically approved by Congress such as military barracks and hospitals,” Mr. Alexander said in a speech on the Senate floor Thursday. “And it also avoids months or years of litigation, which could make it unlikely the full 234 miles are ever built.”
Others like Senator Martha McSally, Republican of Arizona, have said that they are seeking assurances that key military construction projects will not be affected. In a private lunch with Vice President Mike Pence last week, lawmakers asked for details about what projects would be affected. The Defense Department has not released that information.
Senator Roy Blunt, Republican of Missouri and another member of the Appropriations Committee, has also expressed misgivings about Mr. Trump upsetting the panel’s handiwork.
The Strict Constitutionalists: Not in Congress’s lane.
Multiple Republican senators have expressed unease about the precedent set by the declaration and the potential that a future Democratic president could use a national emergency declaration for liberal purposes, once Congress forfeits its exclusive, constitutionally granted power of the purse.
Senators Marco Rubio of Florida, Ted Cruz of Texas, and Mike Lee of Utah have all voiced concern on the constitutional question, though none of them has explicitly promised to overturn the emergency declaration.
Mr. Tillis, in an opinion piece published in The Washington Post outlining his argument, warned that conservatives needed to consider what some of the current Democratic presidential candidates would do with a national emergency: implement parts of the Green New Deal to address climate change, or limit access to guns to address gun violence, among other possibilities.
Even Mr. McConnell acknowledged Monday that the precedent was a concern and was part of the reason he had previously “argued, obviously without success, that the president not take this route.”
Supporters of the declaration say that the president is within his rights to use powers that Congress gave him through the National Emergencies Act in the 1970s.
“Using this authority is not and was not my preferred choice,” said Senator John Kennedy, Republican of Louisiana, speaking Sunday on CNN’s “State of the Union.”
But Senator Rand Paul, Republican of Kentucky, in an opinion piece on Fox News published late Sunday, was clear: “In September of 2014, I had these words to say: ‘The president acts like he’s a king. He ignores the Constitution. He arrogantly says, ‘If Congress will not act, then I must,’” Mr. Paul wrote, adding, “I would literally lose my political soul if I decided to treat President Trump different than President Obama.”
Even Mr. McConnell, the first to endorse Mr. Trump’s declaration, declined earlier this week to weigh in on the legality of the measure.
“We’re in the process of weighing that,” Mr. McConnell said when asked at a news conference on Tuesday. “I haven’t reached a total conclusion.”
The Politically Vulnerable: Not this year, please.
Republican senators facing a difficult re-election campaign next year are confronting a dilemma: Stick with Mr. Trump’s core voters or side with swing voters who largely oppose the wall and the emergency declaration to fund it.
Senator Cory Gardner, Republican of Colorado, hailing from a state that voted for Hillary Clinton in 2016 and Barack Obama in 2008 and 2012, may be the most vulnerable Republican up for re-election next year, and he has not declared where he stands on the resolution of disapproval.
Nor has Ms. McSally, another targeted Republican up for election next year for the seat she was appointed to fill after John McCain’s death. Two other Republicans targeted by Democrats, Ms. Collins and Mr. Tillis, have come down on the side of opposing the emergency declaration.
A vote supporting the resolution, framed as a defense of Congress’s constitutional power of the purse — or conversely, a vote in support of Mr. Trump’s policies and use of executive power — could sway voters.