The underlying problem is: California is badly organized.
The spin-off from that is: California is badly managed.
These, plus Term Limits, have created a situation where political power is in the hands of people unresponsive to democratic accountability. The real "rulers" of California are the leaders of the various political parties, voting organizations, and the wealthy funders of both. California government responds to these entities not the people. This leads to the situation where Tax Policy, for instance, is controlled by those who control the actual, instead of the formal, means of power within the state.
Secondly, California government does not completely control Tax ... or any other Public Policy. The US Federal government - Congress - has been passing unfunded mandates, as they are called, which requires expenditures to achieve certain goals or ends but without Federal monies.
During times of inflation (see The Long Cycle by Fischer) the wealthy are able to maintain and extend their financial position by imposing the tax burden(s) on the poor and middle class.
Thus, what needs to happen in California is a complete overhaul of Public Policy to a 'reasonable' alternative which may, or may not, create a tax increase for the majority of the citizens but which certainly would lead to a tax increase on the upper 2% as well as businesses.
The GOP is absolutely controlled by corporate shills and anti-tax zealots. (One of the "special interests" mentioned above.) And has a blocking minority in the state legislature.
The wealthy, having de-facto control of the state government necessarily control Tax policy and so can and have fobbed-off tax increases onto the poor and middle class to the point these groups just can't afford to divert any more of their income to taxes. The GOP won't raise taxes on wealth.
Result: Public Policy impasse and state insolvency.
Term Limits [...] have created a situation where political power is in the hands of people unresponsive to democratic accountability
The question is: what then? Is there any precedent for state insolvency in the U.S.?