The financial abyss facing Illinois' pension systems grows deeper.

The financial news just keeps getting worse for Illinois. Enduring a huge state tax increase, still facing a multibillion-dollar budget deficit and watching Gov. Pat Quinn propose more borrowing and more spending in his recent state spending plan, taxpayers might reasonably wonder what else could go wrong.

Auditor General William Holland recently provided the answer when he reported that the hole in the state's public employee pensions is even worse than previously thought.

The difference between what Illinois has available to pay its public employee retiree pension obligations and what it owes future retirees jumped by 21 percent last year, and it was already outrageously large. The state owes $139 billion in pension obligations to public employees, like teachers and government workers, and it has just $63 billion in assets.

There are, of course, various ways to make up that imbalance. The investments made on behalf of the pension plans could always sore in value, reducing the deficit. There's no question that the ongoing recession accompanied by declines in the value of real estate and stock and bond investments exacerbated it. But the real solution would be for the state to reduce the deficit by stepping up its required contributions to the pension fund.

That, however, is unlikely because every $1 million or $1 billion contributed to public pension funds is $1 million or $1 billion less the state has to fund education, roads, law enforcement or social service programs.

A more likely scenario is Illinois House Speaker Michael Madigan's proposal for the General Assembly to revise its pension obligations for public employees. That will be hard to achieve because public employee unions will vigorously resist any changes, and they have the political muscle to stop it.

Madigan led a legislative effort last year to change retirement rules for public employees hired after Jan. 1, 2011. Union leaders screamed bloody murder then, even though none of their existing members were affected.

Now Madigan is talking about rewriting the rules for employees covered by the old system. It's not only politically problematic, but legally problematic as well. There's considerable disagreement about whether the Illinois Constitution allows modifying the rules for people covered by the old system.

State Senate President John Cullerton contends any changes would violate the Illinois Constitution. Others disagree. Only the Illinois Supreme Court can decide that question with finality.

But Illinois still would have a big problem even if modifications are permitted. Too many promises over too much time by too many irresponsible elected officials have led to a disastrous situation. That's one of the reasons why Illinois is bankrupt.