Democrats on Tuesday pushed unprecedented legislation through the House to block President Trump's national emergency declaration to steer billions of extra dollars to his southern border wall, raising the prospect that Trump might issue his first-ever veto to defeat the effort.

The vote was 245-182, with all Democrats voting yea and 13 Republicans joining them.

Tuesday's vote marked the first time the House or Senate has tried to terminate a presidential declaration of a national emergency, using the provisions of the National Emergencies Act of 1976. Former Rep. George Miller, D-Calif., attempted a similar effort regarding a national emergency declared by then-President George W. Bush, but the measure never came to a vote on the House floor.

Should enough Republicans in the GOP-controlled Senate defect and support the House bill, a two-thirds supermajority in both the Senate and House would be needed to override Trump's veto. The White House issued a formal veto threat Tuesday ahead of the House vote, ramping up pressure on Republicans to hold the line. (With 427 representatives voting, the House needed 285 yeas to have a veto-proof margin on this legislation, and fell far short.)

It took President George W. Bush more than five years before he used his veto, and President Barack Obama only 11 months. For President Bill Clinton, it took two and a half years.

Senate Majority Leader Mitch McConnell, R-Ky., has said he expects the measure to come before the Senate by mid-March. With three Senate Republicans saying they would support the legislation, only one more was needed to vote with all the Democrats to pass the measure and send it to Trump.

"When you see the vote today there will be nowhere near the votes to override a veto," House GOP Whip Steve Scalise, R-La., told reporters.

Even many GOP lawmakers who have viewed themselves as protectors of Congress' power of the purse said they would defer to Trump in this case, saying he has the authority under the mid-1970s emergencies statute.

"They love Trump in my district," said Rep. Billy Long, R-Mo. "I'm for Trump."

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Democratic leaders said the vote was not about the merits of Trump's wall but how Trump was trampling on the Constitution by grabbing money that he couldn't obtain through the usual means.

House Speaker Nancy Pelosi, D-Calif., said Trump's action "steals billions of dollars" from military construction projects— including, possibly, family housing and child care centers — to build the wall along the Mexico border.

Republicans have countered that problems with drug runners and human trafficking gave merit to Trump's maneuver.

"I went down there neutral on this question, didn't know whether or not I'd support a national emergency," said Rep. Adam Kinzinger, R-Ill., who recently returned from a National Guard deployment along the border in Arizona. "And, I came back more convinced than probably anybody that this is the right thing to do."

"If Republicans vote their beliefs, we'll get a lot. If they vote their party, we won't get a lot," said House Majority Leader Steny Hoyer, D-Md.

Trump on Monday urged Senate Republicans to stick with him.

"I hope our great Republican Senators don't get led down the path of weak and ineffective Border Security," Trump tweeted. "Without strong Borders, we don't have a Country — and the voters are on board with us. Be strong and smart, don't fall into the Democrats 'trap' of Open Borders and Crime!"

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Vice President Mike Pence discussed the issue with GOP senators during their weekly private lunch. In a statement after the sit-down, South Carolina Republican Sen. Lindsey Graham accused Democrats of hypocritically changing their mind about realities on the southern border.

“We had a great presentation from Vice President Pence and his team regarding the emergency declaration and the need for additional spending to protect our southern border," Graham said. "The Vice President made a compelling case that the border crisis is real and President Trump has both the authority and legal backing to declare a national emergency."

Graham added: "In 2014, President Obama declared a humanitarian crisis at our southern border because 120,000 unaccompanied minors were apprehended. As of today, we have already apprehended 120,000 in Fiscal Year 2019. The problems of 2014 are only getting worse."

Senate Democratic leader Chuck Schumer of New York said Trump was trying to "bend the law" with his declaration of a national emergency on the southern border. He called on lawmakers to "speak up with one bipartisan voice" to put a check on the executive branch as the founding founders envisioned.

"What would stop a future president from claiming an emergency every week?" he asked.

On Monday, GOP Sen. Thom Tillis, R-N.C., said he would vote to block the order, joining Maine's Susan Collins and Alaska's Lisa Murkowski as Republicans supporting the resolution. Congress must defend its power of the purse and warned that a future Democrat in the White House might abuse the power to advance "radical policies," Tillis said.

Another Republican, Sen. Lamar Alexander of Tennessee, called Trump's order "unnecessary, unwise, and inconsistent with the United States Constitution and I'll decide how to vote when I'm presented with something to vote on."

Senate voting on Trump's emergency order could drag under a rarely used procedure, which an aide said is possibly a first for the chamber. The law allows for up to 15 days of committee review— in this case, at the Armed Services panel — with a full Senate vote three days later. Senators, though, said the process could be expedited.

At issue is Trump's longstanding vow to build a wall along the 1,900-mile southwest border, perhaps his top campaign promise. He has long since dropped any pretense that money for the wall would come from Mexico, which he once claimed would be the source of funding.

Earlier this month Congress approved a huge spending bill providing nearly $1.4 billion to build 55 miles of border barriers in Texas' Rio Grande Valley, ending a dispute that had led to a record 35-day partial shutdown of the government. Trump had demanded $5.7 billion to construct more than 200 miles.

Trump's declaration of a national emergency gives him access to about $3.6 billion in funding for military construction projects to divert to border fencing. Lawmakers in both parties are recoiling at the politically toxic prospect of losing cherished projects at back-home military bases. The Defense Department has not identified which projects may face the ax.

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But, the administration is more likely to tap $600 million from a federal asset forfeiture fund first. In addition, it is considering shifting more than $2 billion from Defense Department accounts into a Pentagon counter-drug fund to be tapped for wall construction.

Trump's edict is also being challenged in the federal courts, where a host of Democratic-led states such as California are among those that have sued to overturn the order. The House may also join in.

Fox News' Chad Pergram, Alex Pappas and The Associated Press contributed to this report.