US states aren't allowed to secede. Not even Texas. The US government would lose so much prestige from the loss of a state, that they would never allow it. So it would require some kind of armed conflict that no one state could ever win.
Are you really certain that the federal government would send the military in to prevent a state seceding if secession was clearly the democratic will of the people of the state? I wouldn't rule out the possibility but I think it would be an unlikely outcome.
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.