I’m assuming there would have been a case by that time. If Congress passed a law, or Trump an executive order interepreting the extant statute, the immigration groups would file suit immediately and it would probably go the heavily-Communist SCOTUS in under two years.
That’s assuming President Trump hasn’t replaced Anthony Kennedy or one of the consistently Liberal Justices by the time such a case reached the Court. If he’s able to do so, he would likely be facing a friendly Supreme Court.