That will be a quickly dismissed suit. Sanctuary cities are entirely legal under our immigration law.
They would not exist otherwise. There is no obligation of local law enforcement to cooperate with ICE unless the federal government follows its own due process procedures for doing so. ICE being lazy phuqs never bother to do so
The thing is the Federal government has to follow its own rules and due process procedures if it wants cooperation from local law enforcement. Sanctuary cities do not impede ICE actions if ICE bothers to do things properly. But they typically don’t.
Arizona was using immigration as an excuse to engage in harassment, theft, and systematic racism.