Alas, they really aren't. States don't go bankrupt ~ they just run out of money and quit paying their bills. Even their debts have no asset resources behind them. Investors can and will be burned.
A piece of history is instructive. As you drive through the Midwest on your way to the mountains, or the West, notice the very nice old county courthouses that were built in the 1800s. Some of them are incredibly like French chateaux.
Smart guys would print up bonds and sell them in Europe for the purpose of financing a fine court house in some county in the middle of the continent ~ where there were maybe a hundred farmers!
Europeans thinking they were buying into the future of America invested in these bonds.
True enough most of the courthouses were built, but the bonds were never redeemed.
You can still rent a chunk of property-tax free land on a canal company route ~ in Indiana! State went through two technical bankruptcies but the canal company outlived everything. They built lousy canals but kept heafty cash reserves. They're still in business!
In the nearterm future you will know who the state government retirees are ~ they'll be working as greeters at Wal-Mart!
He has a future.