How? That's the problem. If some agency in New York has rented accommodations in Milwaukee and moves a dozen Syrians into them then how can Wisconsin enforce their ban on the Syrians? The can't arrest them - no crime has been committed. They can't sic the INS on them - they're here legally. They can't deny them any state assistance - not unless they also deny the assistance to other foreigners here legally. Unless Congress puts an end to it - fat chance on that - then it looks liker there isn't anything the states can do about it.
Arrest the Feds and make the Supremes rule.
Oh...the crime is Endangering the public/Reckless endangerment. Non vetted immigrants. Add ‘Under color of Authority and make it a RICO case.