Sanctuary Cities

[Zorro!]

SUPREMACY CLAUSE: Justice and DHS reject state restrictions on ICE arrests at state courthouses.

The supremacy clause has to do with feds having priority over states when all else is equal.
But ICE is not at all equal to most state functions.
An immigration violation is not criminal, but only a regulatory infraction, similar to a parking ticket or forgetting to file your taxes on time.
So ICE has no priority at all over states when it comes to immigrants who are in custody for something else.
Nor is it legal for state enforcement to act on federal laws.
That is an overt violation of jurisdiction.
So as much as the feds want states to do their work for them, that is illegal and they can not do it.
All states are supposed to be sanctuary sites by law.

Repeat illegal entry is a felony.

It's safer for all involved to arrest felons while already in custody.

ICE and CBP officers are not subject to state rules that purport to restrict ICE and CBP from making administrative arrests on property that is otherwise open to the public and other law enforcement officers. Under the Supremacy Clause of the United States Constitution, such rules cannot and will not govern the conduct of federal officers acting pursuant to duly enacted laws passed by Congress when those laws provide the authority to make administrative arrests of removable aliens inside the United States.