http://blog.constitutioncenter.org/...egal-non-citizens-violate-the-14th-amendment/
There is, of course, a basic constitutional understanding that a sovereign nation has broad power to protect its borders, to decide who may enter its territory, what foreign nationals who enter can do while inside its borders, and how long they may be allowed to stay. Congress basically decides most of those issues by passing laws, but the Executive Branch has very wide discretion to decide the particulars of enforcing those laws.
Neither branch, however, may simply sweep away “life, liberty or property” from undocumented immigrants, just because they lack the proper papers. And neither may the state governments where such immigrants live.
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The biggest constitutional question that hangs over the Trump immigration policy platform, however, is the validity of the idea of mass deportation. If the candidate means that every one of the more than 11 million people now in the U.S. illegally must be sent back home, would Congress have the authority to order that without some justification, individual by individual? In other words, can planes, buses and railroad trains simply be loaded up with illegal residents, and carry them all out of the country nearly instantly?
There is no constitutional right to be in the U.S., or remain in the country, illegally, but would the courts be persuaded that mass deportation was not a race-driven policy? Would the government have to convince the courts, at least, that such an indiscriminate policy of exclusion was actually necessary to serve a valid national policy goal?
It is worth remembering that constitutional history has made a deeply harsh judgment against the policy that rounded up Japanese-Americans and sent them to prison camps, based solely on their racial identity, and the suspicion that that identity made them disloyal to the U.S. Would the courts react differently to a policy that supposes that every foreign national in the country without papers was going to commit a crime or be a threat to national security? What other reason could there be for including every one of them? That kind of broad classification of individuals would be very hard to justify in an era when human rights are now more surely respected.