I think it does more than you give it credit, it puts them in the eyes of their respective populations. At the very least it might make it much harder for them to get re-elected in whatever position they hold. And I don't know if he can cut funding to them based on this, but I'm sure a lawyer can put up a case that the city is endangering the public by allowing illegal immigrants that are also criminals to stay by letting them avoid ICE agents. So yes, it actually does put pressure on them I would think. You don't give the guy enough credit.