Ya, I don't think it is just that they are not welcome, he is asserting that without his permission the move is unconstitutional and they would be operating in his state under an illegal order.

I would loudly and legally take action to argue that the NG has not been properly federalized, and until it is, all NG must follow Pritzger's orders. There ought to be a legal burden that the President must meet to federalize the NG, especially against the Governor's objections.

I think this is the view Pritzker is threatening in may take.