You gotta think about this here. What exactly are they wanting to secede for? Do the benefits outweigh the risks and challenges? I don't think its ever gonna be worth it for a while. Those states, if they seceded, what would they do? They'd have to establish their own economies, military, and all sorts of other things. They aren't prepared for thaf.
However this does always remind me of how the US isn't going to last another fifty years. I bet that by 2060+ the country will have split in two, hopefully peacefully.