The US Code grants it to the president and the US Attorney General. There doesn’t appear to be a restriction on religious tests.
Per 8 USC §1182
(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.”
It’s incredible how this law is basically being ignored.
https://www.law.cornell.edu/uscode/text/8/1182
Great post!
Jimmy Carter didn’t ignore it. He tossed every Iranian here on a visa out of the country and stopped all immigration of Iranians. Trump has since fine tuned his TEMPORARY Muslim moratorium to include those emigrating from terror sponsoring countries.