Democrats in the Illinois state Capitol have set aside debate on a bill to force a special Senate election in favor of impeachment proceedings against Gov. Rod Blagojevich (D), who was arrested last week and charged with attempting to sell President-elect Barack Obama’s vacant Senate seat, among other alleged crimes.

While the state House reportedly voted unanimously to begin impeachment proceedings, the move away from pushing the special election legislation could ensure that Democrats hold onto Obama’s seat.

If Blagojevich is forced from office, either through impeachment or resignation, Lt. Gov. Pat Quinn (D) would become governor and then appoint a successor, keeping the seat in Democratic hands. Republicans have called for a special election to fill the spot, and believe they have an outside chance of winning the seat in a special contest.

“The only thing more audacious than Democrats proposing a special election and going back on their word is that they did it in full view of the public,” Illinois Republican Party Chairman Andy McKenna said Monday evening. “Speaker [Mike] Madigan (D) first supported a vote on special elections legislation, and make no mistake, his actions tonight directly benefit the Democratic Party.”

After Blagojevich was arrested last week, many national Democrats — including Sen. Dick Durbin (D-Ill.) — immediately called for state lawmakers to change the law and set a special election to fill Obama’s seat. Since then, however, many national and local Democrats have backpedaled on the idea of a special statewide election, citing the estimated $50 million price tag and a four-month waiting period before the Senate seat is filled as their reasons.

“The best outcome is if our governor resigns and the lieutenant governor takes over, and we can at least consider the option of an appointment,” Durbin told Roll Call on Dec. 12.