Always remember what a State is. It's a written down state-of-mind, written down because everybody would forget it after a couple of years if it wasn't written.
The only reason the States of the USA are not fighting it out any more than they are, is that they have promised the Federal Government in their contract (enabling act) with the US gov that they wouldn't... at least beyond a certain point.
All the US States (except Louisiana, which does it a different way) have written, right in their various constitutions, that they promise to uphold the Federal Constitution.