Leave the governance to those particular cities. Withholding fed money to law enforcement who work in those cities almost guarantees an eventual breakdown of resources that will be used to push martial law. It's a set up for failure that will cost lives. The better alternative is to provide pathways to citizenship. I would advocate that any criminal act more than a felony or more than 2 felonies means deportation. Sanctuary shouldn't mean untouchable if your a criminal.