WASHINGTON — President Trump on Friday pointed to nearly five dozen previous instances in which presidents of both parties have declared emergencies as justification for his invocation of extraordinary powers to build his border wall. But there is no precedent for what he has just done.
None of the times emergency powers have been invoked since 1976, the year Congress enacted the National Emergencies Act, involved a president making an end run around lawmakers to spend money on a project they had decided against funding. Mr. Trump, by contrast, is challenging the bedrock principle that the legislative branch controls the government’s purse.
“On the surface, this ‘Oh, other presidents do this, too’ line seems logical,” said Chris Edelson, an American University government professor and author of a 2013 book, “Emergency Presidential Power: From the Drafting of the Constitution to the War on Terror.” “But there is no example where a president asked for funding for something from Congress, Congress said, ‘No,’ and the president said, ‘I’ll use emergency powers to do it anyway.’”
Mr. Trump sought to evade that distinction on Friday when he announced his border wall decision at a news conference in the White House Rose Garden. He portrayed his invocation of emergency powers as a routine use of executive authority that was never controversial when his predecessors did it.
“I’m going to be signing a national emergency and it’s been signed many times before,” he said. “It’s been signed by other presidents. From 1977 or so, it gave the presidents the power. There’s rarely been a problem. They sign it. Nobody cares.”
But a list of about 59 previous times when presidents since the Carter administration have invoked emergency powers, compiled for a recent study of presidential emergency powers for the Brennan Center for Justice at New York University School of Law, shows none that look like Mr. Trump’s declaration in crucial respects.
The overwhelming majority of those instances were moves by presidents to impose sanctions on various foreign officials and groups — freezing their assets and making it illegal for Americans to do business with them — for wrongdoing like human rights violations, terrorism or transnational narcotics trafficking. They attracted no controversy because Congress has wanted the executive branch to operate that way.
Congress has also enacted a statute that gave presidents, in a declared emergency “that requires use of the armed forces,” the power to redirect military construction funds to build projects related to that use. It is that statute that Mr. Trump is relying upon, and his administration argues that this means he is exercising authority that lawmakers wanted the presidency to be able to wield.
But Elizabeth Goitein, who oversaw the Brennan Center study, pointed to the widespread dispute over whether, as a matter of empirical reality, there exists a true emergency on the border that would be resolved by a wall, as well as to the fact that Congress already made clear it did not intend to spend extra billions of dollars on Mr. Trump’s wall.
“There is nothing approaching an ‘emergency’ in this situation, no matter how loose a definition you use,” she said. “And Congress has made it as clear as it can that it does not want the president to use funds for this purpose, so this is the president using emergency powers to thwart the will of Congress. That is very different from how emergency powers have been used in the past.”
In a briefing with reporters on Friday, the White House identified only two previous instances in which presidents relied on emergency powers to spend funds on something different than what Congress had appropriated them for. Both involved military construction associated with wars: one under President George Bush’s Persian Gulf war emergency declaration, the other under President George W. Bush’s emergency declaration after the Sept. 11 attacks. Neither funded projects that Congress had previously weighed and rejected.
The idea behind emergency powers laws is that Congress wanted the president to have standby authorities to activate in a crisis, when the government must respond quickly. The Brennan Center study identified 123 such statutes.
In the 1976 act, Congress turned off numerous old “emergencies” that had been lingering for many years and created a process presidents must follow when invoking such statutes. But the overhaul did not include defining limits on when a president could decide that a qualifying emergency existed, preserving White House flexibility.
One check against abuse of that power eroded quickly: Congress had intended for lawmakers to have the power to overrule a president’s declaration by passing a resolution with a simple majority vote. After a 1983 Supreme Court ruling, however, presidents gained the power to veto such resolutions. That weakened Congress’s hand because it takes two-thirds of both chambers to override a veto.
The other check against abuse has been self-restraint: Presidents have self-regulated and not invoked emergency powers to achieve policy goals Congress had rejected — or claimed that a qualifying crisis existed in disputed circumstances.
Much of the criticism of Mr. Trump’s move has centered on fears that he was expanding executive power by establishing a precedent that future presidents — including Democrats seeking liberal ends — may someday use to circumvent Congress, too. On Friday, Mr. Trump dismissed a question from a reporter about that worry.
“The people that say we create precedent — well, what do you have, 56, or a lot of times — well, that’s creating precedent, and many of those are far less important than having a border,” he said.
But several legal experts said there was another possible long-term consequence that had received less discussion: by violating that norm of self-restraint, Mr. Trump may prompt Congress to eventually take back some of that power from the presidency — at least in a post-Trump era, when a succeeding president might be willing, or believe that it is politically necessary, to sign such a bill.
Notably, Representative Jerrold Nadler, Democrat of New York and the chairman of the House Judiciary Committee, on Friday accused Mr. Trump of “a gross abuse of power that subverts the key principles laid out in the Constitution” over which branch controls the appropriation of funds, and announced an investigation. In 1976, it was the House Judiciary Committee that drafted the National Emergencies Act.
Stephen I. Vladeck, a law professor at the University of Texas, Austin, said that legislators may react to Mr. Trump’s move by enacting a new overhaul of those laws that tightened restrictions on when a president could use them.
Lawmakers could, for example, impose a strict definition of what qualifies as an emergency, taking away presidential flexibility to deal with unforeseen circumstances. Congress could also attach “sunset” clauses to emergency statutes, so that the president's special powers would automatically deactivate after a month or two without new action by lawmakers to extend them.
“The risk the president runs is that Congress will take away much, if not most, of the discretion it’s given to the president,” Mr. Vladeck said. “And then the concern is that Congress could hamstring a future president from having all the tools he or she might need to react to a future emergency. So a short-term win for the president could become a long-term loss for the presidency.”