I would imagine that Texas and Alaska, two states that I think could stand as their own countries, would be the first to leave (again).
It is going to go down like this... first... countries like China simply are going to stop lending money to us because they know that with over a hundred trillion dollars of unfunded liabilities, there is simply no way the US government can pay the interest on the debt, much less any principal.
Second, because the need for money still won't be contained, the US will simply resort to printing more money. Both of these moves will make the US dollar even more worthless than it is.
Third, since no welfare program ever gets cut, and demand always increases, defense will be gutted to help pay for pay for welfare. Though at that point it will be moot because worthless dollars cannot buy advanced military technology, and I cannot imagine that soldiers are going to put their lives on the line for nothing.
Without a real currency, and without a military, states which want freedom will be able to leave very easily, and foreign powers will be able to take for themselves what is left. It will be just like what happened to the Western Roman Empire. It was so burdened by government expenditures that it simply had to abandon vast swaths of territory because it could not afford to pay its military to defend them, and in the end enemies from without were able to take for themselves what was left.
My daughter is one year old now. And I do not imagine that the country she will end up growing old in will be the United States of America.
This will be solved only by the spilling of blood.