SAN FRANCISCO (CBS SF) — President Trump repeated his claim Sunday that he may build the border wall without Congress’s approval by declaring a national emergency at the the U.S.-Mexico border.

“I may declare a national emergency dependent on what’s going to happen over the next few days,” he told reporters after arriving at the White House from a trip to Camp David.

This comes after numerous, failed rounds of negotiations between the White House and Congress to fully re-open the government.

House Speaker Nancy Pelosi (D-CA) told Jane Pauley on CBS Sunday Morning that the president wants to have all the power in government.

“The impression you get from the president is he would not only like to close government, but also build a wall and abolish Congress, so the only voice that mattered was his own,” she said.

Congressman Adam Schiff (D-CA) is the chairman of the House Intelligence Committee and he says the president’s plan to declare a national emergency won’t wash.

“Look, if Harry Truman couldn’t nationalize the steel industry during wartime, this president doesn’t have the power to declare an emergency and build a multi billion-dollar wall on the border, so, that’s a nonstarter,” he told CNN’s Jake Tapper.

The U.S. Supreme Court case of Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579 (1952) did shoot down Truman’s plan to nationalize the steel industry during wartime.

According to the Court summary, “To avert a nation-wide strike of steel workers in April 1952, which he believed would jeopardize national defense, the president issued an Executive Order directing the. Secretary of Commerce to seize and operate most of the steel mills.”

Importantly, “The Order was not based upon any specific statutory authority but was. based generally upon all powers vested in the president by the Constitution and laws of the United States and as President of the United States and Commander in Chief of the Armed Forces.”

The Court dismissed the Truman administration’s claims that the Commander in Chief has the right to interfere in labor disputes by seizing private property, writing, “Even though ‘theater of war’ be an expanding concept, we cannot with faithfulness to our constitutional system hold that the Commander in Chief of the Armed Forces has the ultimate power as such to take possession of private property in order to keep labor disputes from stopping production.”

President Trump’s proposal appears somewhat different than Truman’s, as Trump is not asking to seize private property, although depending on where the barriers would go, that could be part of the process. Also, where Truman relied exclusively on the U.S. Constitution, Trump is probably relying on federal laws passed in the decades since the Youngstown case in 1952.

The Brennan Center for Justice has identified 136 statutory powers that may become available to the president upon declaration of a national emergency. At least one high-powered Democrat believes the law is on Trump’s side, with a catch.

Representative Adam Smith (D-WA) is the new Chairman of the House Armed Services Committee and on ABC’s This Week, he was asked by George Stephanopoulos whether the president could declare a national emergency and have the military build the wall.

“Well, unfortunately, the short answer is yes,” Smith replied. “There is a provision in law that says the president can declare an emergency. It’s been done a number of times. But primarily, it’s been done to build facilities in Afghanistan and Iraq.”

He said there would still be a legal issue. “In this case, I think the president would be wide open to a court challenge saying, ‘Where is the emergency?’ You have to establish that in order to do this. But beyond that, this would be a terrible use of Department of Defense dollars.”

Smith did not specify the law to which he referred, but it may be 50 U.S.C. 1431-1435. This 1958 law says, “The President may authorize any department or agency of the Government which exercises functions in connection with the national defense…to enter into contracts or into amendments or modifications of contracts heretofore or hereafter made and to make advance payments thereon…whenever he deems that such action would facilitate the national defense.”

The President has to notify Congress, but there is no apparent provision for Congress to stop the contract.  Any law to stop it would need the President’s signature or a veto-proof super majority.

One might argue that the law (50 U.S.C. 1431-1435) allows the President to enter into a contract with a construction company to build some sort of structure on the border or several structures in strategic places so long as he deems it in the “national defense.” Of course, this is just one law that relates to the President’s powers and he may be relying on some other statute(s).

Whatever the Trump administrations’ legal reasoning, any move to declare an emergency and build a wall will undoubtedly be met with multiple lawsuits. So it is not completely clear that an emergency declaration would be the faster alternative to continued negotiations.