UPDATE, 9:50 p.m. — The full Senate approved the 5 percent income tax tonight. Still looks unlikely that the House will touch any tax hike like this.

UPDATE, 5 p.m. — This passed the committee on a partisan vote, and could be debated on the Senate floor tonight. Passage is possible.

SPRINGFIELD, Ill. - The Illinois Senate today appears poised to take up a proposed income tax hike - one that’s even higher than the one that Gov. Pat Quinn has already proposed.

Senate President John Cullerton’s office has announced that the Senate Education Committee will take up HB174 any time now. It would hike the state’s 3 percent flat-rate income tax to a full 5 percent. That increase would be offset by property tax cuts and a more generous personal exemption level ($3,000 per person off a household’s taxable income, up from the current $2,000). Supporters say the plan would raise about $5.6 billion, to be earmarked heavily toward more education funding.

Quinn has spent months trying to convince lawmakers to hike the income tax to 4.5 percent to address a crushing state budget deficit, and with Sunday’s budget deadline approaching, he still hasn’t been able to get them to do it. So how anyone expects an even higher tax proposal to advance is a good question.

Here’s a few possible answers:

- The latest proposal would raise more money for the state than Quinn’s plan (by about $1.5 billion), thus giving lawmakers more of a reason to go out on the limb of supporting a tax hike.

- The new plan is earmarked specifically for education, which to many people is a better reason to raise taxes than merely balancing the state budget.

- The new plan’s offsetting property-tax cuts will be viewed as a good trade-off in regions where property taxes are out of control and viewed as a bigger problem than the income tax.

- No one actually expects this new proposal to go anywhere; they just want to vote on something that will allow them to go home to their constituents and claim they fought the good fight on behalf of education, without actually having to institute a politically dangerous tax hike.

State lawmakers this weekend are trying to come to agreement on a new state budget and other issues before a midnight Sunday adjournment deadline. After that, new rules kick in that will make it more difficult to pass anything, opening the possibility of a Blagojevich-esque meltdown of state government operations and services.