Democrats in the Illinois Senate tried to take a hostage at the end of the just-completed legislative session in Springfield. They wanted more spending on schools and social programs than the $33.2 billion budget that had originated in the House included. So they added another $431 million in spending to a separate piece of legislation — an annual authorization bill for capital spending. House members refused to be victims of that attempted extortion.

Gov. Pat Quinn responded that, for lack of an authorization bill, he would have to shut down construction projects statewide, idling 52,000 workers. The Senate Dems figured that Quinn would join their cause and push for a bill including their added spending. Wrong. Quinn said this week that he doesn't want a fight over unrelated spending to kill construction jobs. He wants the Senate to approve the same "clean" capital authorization bill that the House already has passed.

So the attempted hostage-taking by Senate Democrats was a flop. Thursday afternoon, they caved to reality. The senators, tails 'tween their legs, will gather Wednesday in Springfield to approve the clean House version of the bill.

Case closed? Not at all. In fact, this episode ought to put every taxpayer on red alert: Do Democrats intend to keep the pledges they made in January, when they imposed their 67 percent hike in the individual income tax rate?

At the time, Senate President John Cullerton gave Illinoisans several assurances. Among them: The income tax increase is temporary. And if state government collects more in revenues than we expect, we won't use that money for new spending — we'll apply it to our huge backlog of bills.

But in a statement late Thursday, Cullerton suggested that he'll continue to push for more spending: "There are still major structural deficiencies in the House budget that will become clear in the months ahead. I look forward to having the opportunity to address issues such as the underfunding of education and social service commitments."

In other words, a guy who just lost a fight to raise spending still thinks the budget legislators have sent to Quinn suffers from "underfunding."

We, too, wish public resources were unlimited. But we also see the grim effects of the Democrats' January tax increase: Hard-pressed Illinois families are paying more to support a government that won't aggressively economize or even rein in a runaway pension system. And too many Illinois employers are exploring relocation opportunities in lower-tax states.

So let's all trust the assurances that Democrats in both legislative chambers gave to the people of Illinois in January. And let's agree on a common-sense agenda to make those assurances come true:

•Stop viewing every possible dollar of state revenue as a spending opportunity.

•Use any extra revenue to pay old bills. That is, to return Illinois to solvency.

•Make sure this damaging income tax hike expires on schedule. Or, better yet, reduce spending now so you can retire the tax hike early — preferably before the last employer to leave turns out the lights.

Senate Democrats, thanks for capitulating on the capital bill. But really, you're going to keep pushing for more spending? The most irresponsible thing you can do is to keep spending so, a few years from now, when the temporary tax hike is set to expire, you can declare another financial emergency as reason to make it … permanent.