Illinois Republican Party Chairman Jack Dorgan of Rosemont won't run for another term and will back Cook County Commissioner Tim Schneider of Bartlett to replace him, he announced Monday.
Dorgan, a Rosemont village trustee and Springfield lobbyist, said he's joining Republican Bruce Rauner's campaign for governor to co-chair the Winnetka businessman's finance committee.
The Republican State Central Committee is set to pick a new chairman Saturday in Springfield. Dorgan sits on that committee representing the 5th Congressional District.
Blair Garber of Evanston, who sits on the committee from the 9th Congressional District, is the only other candidate.
But Schneider's backing from both Rauner and Dorgan gives him a clear advantage going into Saturday's vote.
"It has been my great honor to lead the Illinois Republican Party as chairman over the last year, helping position our candidates across Illinois for an incredible victory this November," Dorgan said in a statement.
Dorgan was first elected to the post a year ago following the resignation of Pat Brady of St. Charles, who was nearly ousted from the job after lobbying state lawmakers to vote for same-sex marriage.
Dorgan released his statement jointly with Rauner, whose success or failure at the top of the ticket against Democratic Gov. Pat Quinn is likely to be linked to the party's fate statewide in November.
The party's chairman is tasked with raising money and trying to help its candidates win in November, a big task for a volunteer job in a state that's leaned Democratic statewide in recent years.
The GOP in Illinois has targeted the governor's race as its top priority.