Right. The Federal government is not a Unitary government.
You seem to dance around this question.
What do you think of State Patrol at ports of entry, keeping hordes of unemployed vagrants out? Is that “legal” or “constitutional”?
Again, it is absolutely the federal government’s job to PREVENT INVASION INTO THE STATES (US Const., Art. IV, Sec. 4).
Of course constitutional state sovereignty allows the state to protect its own borders but otherwise preventing invasion is a constitutional mandate of the feds.
YOU seem to be the one dancing around this issue. It is straightforward but if you are a Leftist, then, you may very well try to confuse the issue as you have here. The article is about homelessness and you have moved this conversation to illegal immigration which is invasion.