[JLS]

From Wikipedia:

President Franklin Roosevelt authorized the internment with Executive Order 9066, which allowed local military commanders to designate "military areas" as "exclusion zones", from which "any or all persons may be excluded." Twelve days later, this power was used to declare that all people of Japanese ancestry were excluded from the entire Pacific coast, including all of California and most of Oregon and Washington. Some U.S. residents of German and Italian descent across the country were also arrested and interned when deemed to be security risks on an individual basis (rather than as an entire community). In 1944, the Supreme Court upheld the constitutionality of the exclusion, removal, and detention, arguing that it is permissible to curtail the civil rights of a racial group when there is a "pressing public necessity."[1]

I am not sure the Supreme Court would hold the same today, but then again they just upheld racial dicrimination that the Dims like now so you never know.

[FreedomCalls]

Thanks JLS. I believe that answers it then. IF, and that's a big "if"; somewhere down the line a future President decides to bar Muslim men of age 17-35 from aircraft, that's the authority he/she would use. It's already been used, so there is precedent, and the Supreme Court has declared it constitutional.

There's your answer, CWOJackson. See? Not so difficult to answer is it?