WASHINGTON — President Trump on Friday issued his first veto, rejecting legislation to overturn his declaration of a national emergency to fund a wall along the southwestern border. The bill had attracted significant Republican support in Congress, a rare and notable departure from partisan solidarity.
“Today, I am vetoing this resolution,” Mr. Trump told reporters in the Oval Office. “Congress has the freedom to pass this resolution, and I have the duty to veto it.” The president called the resolution “dangerous,” “reckless” and a “vote against reality.”
Mr. Trump was flanked by Vice President Mike Pence, Attorney General William P. Barr and Kirstjen Nielsen, the homeland security secretary. Mr. Barr said the president’s emergency order was “clearly authorized under the law” and “solidly grounded in law.”
The veto, which was expected, will send the legislation back to Congress, which almost certainly does not have enough votes for an override. That means Mr. Trump’s declaration will remain in effect.
Democrats were quick to condemn the president’s action.
“It is no surprise that the president holds the rule of law and our Constitution in minimal regard,” Senator Chuck Schumer of New York, the Democratic leader, said in a statement. “There is no emergency; Congress has refused to fund his wall multiple times; Mexico won’t pay for it; and a bipartisan majority in both chambers just voted to terminate his fake emergency.”
To that, Speaker Nancy Pelosi added, “The House and Senate resoundingly rejected the president’s lawless power grab, yet the president has chosen to continue to defy the Constitution, the Congress and the will of the American people.”
Mr. Trump has long insisted that there was a security and humanitarian crisis at the border with Mexico, an assertion that was undercut by Mr. Trump himself when he acknowledged that he could have waited to issue a declaration. But on Friday, he offered a flurry of statistics to support his contention, though many were vague. He blurred numbers that reflected a humanitarian problem with those he said represented a security issue.
Democrats had seized on his earlier words and cited other government data that shows there has been no flood of criminal migrants coming into the United States. Some Republicans shared that view.
But others said they opposed the president on the grounds that it was the duty of Congress to appropriate taxpayer dollars and that Mr. Trump had exceeded his authority. On Thursday, a dozen Republicans joined Senate Democrats in voting to overturn Mr. Trump’s emergency declaration, 59 to 41.
“Never before has a president asked for funding, Congress has not provided it and the president then has used the National Emergencies Act of 1976 to spend the money anyway,” Senator Lamar Alexander, Republican of Tennessee, said after the vote. Senator Jerry Moran, Republican of Kansas, said he thought Mr. Trump’s declaration was unconstitutional.
The president said on Friday that he understood why some Republicans believed he had overreached. “They’re doing what they have to do, and I put no pressure on anybody,” Mr. Trump said. “I actually said, ‘I could have gotten some of them to come along.’ I said: ‘I want you to vote your heart. Do what you want to do. I’m not putting any pressure.’”
“I’ll let them know when there’s pressure, O.K.?” he added. “And I told them that. I said, ‘When I need your vote, I’m going to let you know.’ I didn’t need the vote because we all knew it was going to be a veto, and they’re not going to be able to override. It’s going to go very quickly.”
Mr. Trump has held broad sway over congressional Republicans in his first two years in office. The decision by the dozen Senate Republicans to side with Democrats on an issue central to the president’s agenda was seen as a reclaiming of the role of Congress as a coequal branch of government.
Mr. Trump was undeterred by the Republican opposition and quickly signaled his next step when he tweeted “VETO!” not long after the vote. The president said on Friday that there was nothing less than an “invasion” of the United States by migrants, and he added that so many of them had been apprehended that there was “nowhere left to hold all of the people that we’re capturing.”
Even if Congress fails to override the veto, the emergency declaration is already drawing court challenges.
A coalition of 20 states, including California and New York, sued last month over Mr. Trump’s use of emergency powers, arguing that the president does not have the authority to divert funds for building a wall along the Mexican border because it is Congress that controls spending.
Xavier Becerra, the attorney general of California, said that Congress had sent a clear message that “your supposed ‘emergency’ isn’t one.”
He added, “We are determined to stop his fabricated emergency in its tracks.”
Anthony D. Romero, the executive director of the American Civil Liberties Union, said in a statement that “even members of President Trump’s own party are beginning to realize that he is a one-man constitutional crisis.”
“The president’s veto is as meaningless as his signature on the national emergency declaration,” he added. “Congress has rejected the president’s declaration, and now the courts will be the ultimate arbiter of its legality. We look forward to seeing him in court and to the shellacking that he will receive at the hands of an independent judiciary.”