Federal immigration law also includes Section 1182(f), which states: “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”.
The notion that that clause allows the President to override the INA's ban on country-of-origin discrimination was challenged in courts over 40 years ago and proved false. Further, it doesn't pertain at all to lawful permanent residents of the US, so you've also moved the goalposts.
The subtext of these arguments is that we should be less outraged, because green-card-holders were lucky to be here at all and reside in this country knowing they can be removed at any time. That's plainly, flatly, objectively false, in addition to being ethically dubious.
http://www.nationalreview.com/article/444371/donald-trump-ex...