yeah, bye bye sovereign immunity.
While acts of a de facto incumbent of an office lawfully created by law and existing are often held to be binding from reasons of public policy, the acts of a person assuming to fill and perform the duties of an office which does not exist de jure can have no validity whatever in law.
An unconstitutional act is not a law; it confers no rights; it imposes no duties; it affords no protection; it creates no office; it is in legal contemplation as inoperative as though it had never been passed.