In a rebuke of President Trump, the Senate voted 59-41 to pass legislation Thursday afternoon rejecting his national emergency declaration concerning the U.S.-Mexico border.

Twelve Republicans, including Alaska Sen. Lisa Murkowski, joined Democrats in voting to pass the resolution.

In a statement Thursday, Murkowski said her vote was intended to preserve the separation of powers within the federal government.

"Article 1 provides that the power to appropriate lies with the legislative branch. When the executive branch goes around the express intention of Congress on matters within its jurisdiction, we must speak up or legislative acquiescence will erode our constitutional authority," Murkowski said. “We can and must address the President's very legitimate concerns over border security, but we must not do it at the expense of ceding Congress' power of the purse."

Sen. Dan Sullivan, Alaska's junior U.S. senator, said in a statement Thursday that after "much reflection" he voted yes because "there is no doubt that a crisis exists at the border."

"With the influx of drugs, crime, and human trafficking as a result of a porous southern border, I could not vote for a bill that, in effect, would block the President’s attempt—using authority authorized by Congress and previously invoked by numerous Presidents—to better secure the border and keep Americans safe,” Sullivan said.

The president issued his emergency declaration as a way to free up funding to build his long-promised wall along the southern border after Congress refused to provide the $5 billion he originally requested. New budget requests now put that total dollar amount at over $8 billion.

While the bill now moves to the president's desk, Mr. Trump will likely move to issue his fist veto of his presidency thus far after tweeting Thursday morning that he was "prepared" to do so if necessary.

He later told reporters in an Oval Office ceremony, "I'll probably have to veto. And it's not going to be overturned. And we're going to have our whole thing. It's been — the legal scholars all say it's totally constitutional. It's very important it's really a border security vote. It's pure and simple it's a vote for border security, it's a vote for no crime."

The House passed its version of the resolution last week, largely along party lines.

Leading up to Thursday's vote, many senators, including Republicans, called out the president's order as an abuse of emergency powers, claiming it could set a dangerous precedent.

"It's a question about the balance of power that is core to our constitution," Sen. Mitt Romney, R-Utah, told reporters on Thursday.  Sen. Lamar Alexander, R-Tennessee, in speech on the senate floor echoed his colleague, saying "This declaration is a dangerous precedent."  

Sen. Jerry Moran, R-Kansas, meanwhile said that while he supports Mr. Trump's goals of securing the border, "this continues our country down the path of all powerful executive – something those who wrote the Constitution were fearful of. 

In an apparent flip, just moments before the senate's vote, Sen. Thom Tillis, R-North Carolina, announced that he would vote against the resolution -- a change in his position from when he wrote in an opinion piece for the Washington Post that he could not support the national emergency declaration. Tillis had written that as a conservative he couldn't endorse a precedent that "future left-wing presidents will exploit to advance radical policies."

Meanwhile, Senate Minority Leader Chuck Schumer told his colleagues, "The beauty of this government demands that we rise to the occasion this afternoon."

"Let's keep our government with the same balance of power that has served us so well for the past two centuries," he added. 

Here are the Republicans who voted in support of the resolution of disapproval:

  • Sen. Lamar Alexander, Tennessee
  • Sen. Roy Blunt, Missouri
  • Sen. Susan Collins, Maine
  • Sen. Mike Lee, Utah
  • Sen. Jerry Moran, Kansas
  • Sen. Lisa Murkowski, Alaska
  • Sen. Rand Paul, Kentucky
  • Sen. Rob Portman, Ohio
  • Sen. Mitt Romney, Utah
  • Sen. Marco Rubio, Florida
  • Sen. Pat Toomey, Pennsylvania
  • Sen. Roger Wicker, Mississippi

Republican Sens. John Cornyn, Thom Tillis, Cory Gardner, Ted Cruz and Ben Sasse sided with Mr. Trump by voting against the resolution. 

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