Hypothetically what would happen if the state decided to reform these pensions, slashing them right back to something they could realistically afford?
With your example, if California tried that before declaring bankruptcy, there would be court challenges that California would lose. Even if contracts going forward were amended, that wouldn't help the structural problems from what has already happened.
Therefore California requires either bankruptcy or extraordinary assistance. And the Obama administration has indicated that no extraordinary assistance will be forthcoming.
It is worth noting here that California is one of the few states that pays more into the federal government than we get out, and the amount extra we have paid in over the years is more than enough to rescue the state government.
From: http://www.leginfo.ca.gov/.const/.article_4
Const., Art. IV, Sec. 12 actually stipulates
" (d) No bill except the budget bill may contain more than one item of appropriation, and that for one certain, expressed purpose. Appropriations from the General Fund of the State, except appropriations for the public schools, are void unless passed in each house by rollcall vote entered in the journal, two-thirds of the membership concurring."