SPRINGFIELD - Illinois Lt. Gov. Pat Quinn, who stands to become the state's chief executive if Gov. Rod Blagojevich quits or is impeached, urged his fellow Democrat Thursday to do the "right thing" and resign from office, "hopefully today."

But if that doesn't happen, Quinn recommended state lawmakers spend their time at the Capitol pushing an impeachment of Blagojevich rather than trying to change state law and strip the governor of his ability to name President-elect Barack Obama's replacement in the U.S. Senate.

If he becomes governor, Quinn said he would move quickly to fill the seat rather than wait for a special election, saying Illinois deserves a "full voice" in Washington during crucial economic times.

Republican lawmakers scoffed at the idea of Blagojevich's lieutenant governor making the pick. Incoming Illinois Senate Republican leader Christine Radogno said there's no way an appointment could be "free from the stench of this corrupt administration."

"This decision absolutely must be made by the voters of Illinois," Radogno said.

In addition, Quinn's appointment push Thursday is a turnaround from his traditional stance on numerous issues in which he's repeatedly called for state voters to have the final say rather than politicians. Most recently he was a strident backer of adding a recall provision to the Illinois Constitution.

Quinn explained the apparent conflict to reporters, saying the cost of a special election - estimated to be in the tens of millions - and the months Illinois would be without full representation led him to believe that the power should remain with the governor.

He promised a "transparent" process for picking a senator and said he'd move quickly if and when he moves up. However, he would not name favorites for the Senate seat and could not describe the process he'd use to ensure public confidence in the selection.

Quinn went to lengths to distance himself from Blagojevich, his running mate in 2002 and 2006. Quinn reminded reporters that the lieutenant governor runs independent of the governor in the primary.

He said he hadn't spoken to Blagojevich since a law-signing event in August 2007, nor has he had any contact with Obama or his transition team regarding a Senate successor.

Quinn said he's often criticized Blagojevich's policies, but he admitted he may have made a mistake two years ago in vouching for the governor.

In 2006, when questions arose about Blagojevich's daughter getting a $1,500 check from a family friend whose wife got a state job, Quinn said he saw nothing wrong with it.

"He's always been a person who's honest and one of integrity," Quinn told reporters then. "I have confidence the governor does the right thing all the time."

Reminded of those comments, Quinn said: "Maybe I made a mistake there."