That prompted 10 senators to look into how sweeping Trump believes his emergency powers are.

They have asked to see this administration’s Presidential Emergency Action Documents, or PEADs. The little-known, classified documents are essentially planning papers.

The documents don’t give a president authority beyond what’s in the Constitution. But they outline what powers a president believes that the Constitution gives him to deal with national emergencies. The senators think the documents would provide them a window into how this White House interprets presidential emergency powers.

“Somebody needs to look at these things,” Sen. Angus King, I-Maine, said in a telephone interview. “This is a case where the president can declare an emergency and then say, ‘Because there’s an emergency, I can do this, this and this.’”