If you believe that the secession of the Southern states in 1860-61 was done in a legal manner, then why should California's leaving require anything more than a declaration that they're gone, and a mad scramble for every bit of federal property that wasn't nailed down?
I would very much like to see the Coastal part of California leave the Union. As I mentioned in another thread, we would all feel as did former Reagan official Charles M. Lichenstein, who said about the U.N.:
"The members of the U.S. mission to the United Nations will be down at the dockside waving you a fond farewell as you sail off into the sunset."
I have no quibble with California's right to secede, and I do in fact want them to secede. If we could send New York and Oregon after them, so much the better!
The *ONLY* issue, and I do mean the only issue, is the Debt they have created for the rest of us, which we will have to pay if they do not. Seeing as how the National Debt stands near 20 trillion, and how the National unfunded obligations stand closer to 100 trillion, there is the small matter of making them pay for their bills before they leave.
Now here is where I expect you to seize on this statement and attempt to apply it to the Southern States which seceded. The only problem with this is that the Southern states tried to pay their obligations, but Lincoln was having none of it, because the moment he accepted the notion that they can pay their bills and leave, his entire argument to force them to remain in the Union collapses.
I also doubt California can pay their bills to the Nation. Hell, they can't even balance their own state budget.