Immigration is de facto controlled unilaterally by the executive, because the Supreme Court declines to engage with the issue, meaning constitutionality is not

Immigration is de facto controlled unilaterally by the executive, because the Supreme Court declines to engage with the issue, meaning constitutionality is not considered, meaning legislation isn't enforced. The constitution in fact doesn't contemplate immigration at all. For that matter, the scope of the Supreme Court's authority isn't well-defined, either, even on issues we routinely see them rule on today. This is why Marbury v Madison was so pivotal for expanding their scope on sheer force of institutional faith. This is the mechanism under which immigration policy can swing so wildly from one administration to the next. There's some sense to it in terms of responding to emergencies and such but it sure does suck in some principled or ethical ways.