"The Immigration and Nationality Act (INA) provides that individual aliens outside the United States are “inadmissible”—or barred from admission to the country—on health, criminal, security, and other grounds set forth in the INA. However, the INA also grants the Executive several broader authorities that could be used to exclude certain individual aliens or classes of aliens for reasons that are not specifically prescribed in the INA.
Section 212(f) of the INA is arguably the broadest and best known of these authorities. It
provides, in relevant part, that:
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..."
Executive Authority and aliens