[Mariner]

"The president has the legal authority to ban people from any nation and class that he deems detrimental to the interests of the US."

It's my understanding that is the exclusive domain of the Congress.

Am I mistaken?

[Blood of Tyrants]

(f) Suspension of entry or imposition of restrictions by President

Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate.

https://www.law.cornell.edu/uscode/text/8/1182