Sheeeeeyit. It's impossible for states to encact treaties with foreign government but that didn't stop Jerry "Flush it Down" Brown.
demonicRATS don't give a flying fig about rules or or laws or Constitutions.
To them, those are all more like guidelines than a set of hard and fast rules. They're a bunch of Capt. Barbossas.
States don't want to do it but technically, each state has unlimited taxing power.
Probably a pretty tough sell telling a judge that you're broke when you actually "have access to all the money you need but you don't want to go there".
States also might consider selling some of the property they own. Lots of cash there.
Illinois just recently sold the Jim Thompson state office building in Chitcago. IIRC, it's been sitting empty and falling apart. I think that the state got about $400M for it.
There's plenty of money, just not enough to cover all of the crazy-azz spending the democrats love.