I think the funniest thing that could happen is the effective gutting of the Rxecutive branch due to Musk and the rest of Trumps toadies. Most of the power of the Executive is soft based around things like the department of education, if the states gain nothing or even lose something from working with the feds they could very well ignore it. This is usually something the Red states do but they dont have enough actual power both economic and social to force anything, but California has enough by itself to light a fire under the ass of all the states if need be.