Here's a good place to "make a stand".
We know that this particular agency (a city jail) is violating immigration law.
OK -- send in ICE agents, backed by armed federal marshals, backed up by U.S. troops if necessary.
March in and clean that place up.
Offer the warden of that jail a choice: cooperate, or be arrested.
If he won't cooperate, arrest him and march him out with the cameras recording.
And then repeat with his "next-in-line", as much as necessary.
Sooner or later, someone will get the message!