CHICAGO — Illinois plunged deeper into turmoil Friday over Gov. Rod Blagojevich as the attorney general asked the state's highest court to strip the scandal-plagued governor of his powers.

But Blagojevich showed no sign of backing down. He took time to pray with ministers at his home and signed a bill that extends insurance coverage for autistic kids, sending a sign to his critics that he's still in charge.

Attorney General Lisa Madigan asked the Supreme Court to declare Blagojevich unfit to serve, likening his corruption scandal to a debilitating illness. The move seeks to hand power over to the lieutenant governor.

The attorney general is applying a rule that was intended to cover cases in which a governor is incapacitated for health reasons.

The Democrat is "unable to serve as governor due to disability and should not rightfully continue to hold that office," according to the motion.

The attorney general, also a Democrat, asked the court to strip the governor of his duties until possible impeachment proceedings and his criminal case run their course. If he does not step down and is not impeached or convicted, Blagojevich could go to the court and ask to be reinstated.

The scandal also has begun to impede state business, Madigan said.

Illinois has billions of dollars in unpaid bills, including payments to Medicaid patients, and the state has approved $1.4 billion in short-term borrowing to keep cash flowing. But before the borrowing takes effect, Madigan said, she has to certify that there is no legal proceeding threatening the ability of the governor to hold his office. In light of the filing by her office, Madigan said, she can't sign that.

Blagojevich faces talk of impeachment when lawmakers gather Monday in Springfield. Because that process could take several weeks, Madigan said, she felt compelled to go to the Supreme Court to deal with Blagojevich in quicker fashion.

Also Friday, John Harris, the governor's chief of staff, resigned. He was arrested with his boss on corruption charges. Harris' attorney, Jim Sotos, said his client resigned "because it was the right thing to do, and that's all I'm going to say."

Blagojevich faces corruption allegations including putting President-elect Barack Obama's Senate seat up for sale.

The Chicago Tribune reported Friday night that Rahm Emanuel, Obama's pick to be White House chief of staff, had conversations with Blagojevich's administration about who would replace Obama in the Senate. The report said there was no suggestion that Emanuel was involved in any dealmaking for the seat.

Blagojevich began the day praying with several ministers in his home, telling them he is innocent and will be vindicated.