They would also lose the appropriate congressional representation and be required to reapply for statehood once they showed they could manage their financial affairs.
If only a portion of that territory was able to do so, they could apply for statehood separately.
So let's say California declared bankruptcy and, following the waiting period, only portions of rural California were able to demonstrate solvency, they could be admitted as separate states.
If there is a better suggestion on solving the public employee union pension crisis without dragging the entire country down, then I have yet to hear it.
I worked with a public employee union for years. I had to attend a speech from an investment manager from CALPERS and he was bragging about how, unlike private employers, they can make any pension deals they want to because CA cannot file bankruptcy and it has the power to raise taxes as much as needed to pay pension liabilities.