Near the end of the Obama reign - there was legislation that was targeted ostensibly at Puerto Rico, seeking to amend the bankruptcy code to allow non-states to use Chapter 9 of bankruptcy. Right now, and at that time, only municipalities (sub-units of states) are able to access Chapter 9 (see Detroit.) While the focus was on opening the door to the territory of PR, the negotiation in the Senate and House were drifting in the direction of Democratic proposals to expand the definition of eligibility to include ambiguous terms that would allow a state to file and be a debtor in Chapter 9. That didn't happen, but I thought at the time it was happening as a favor to Obama on his way out of office - which would allow the State of Illinois to enter bankruptcy to modify the pension obligations. Didn't happen. Instead, an outboard process was created for Puerto Rico that was like Chapter 9 but only exercisable by PR, and not a state. You can bet that Obama wanted to throw a bone to his "home" state as a lame duck, but he couldn't get it done.
Illinois has the problem of having a state Constitutional provision that says, the pension and retirement benefits of public employees shall not be reduced. The legislature made unrealistically high assumption about the return on investments by the pension trust fund authorities, and failed to pay in enough tax revenue over the years so that there are only two ways out a) find a way to earn way above market returns with little or no risk, or b) jack up tax rates to fund dramatically higher contributions. It is the second approach that is driving folks out of the state. With no way to reduce payments to retirees, the only solution is to increase contributions from taxpayers.
Hence, folks gonna vote with they feetz!