Lake County Commissioner Aaron Lawlor will challenge Chairman David Stolman for the board's leadership during a specially scheduled meeting Monday, officials confirmed.
The faceoff between the two Republicans will be the first interparty showdown for the big chair since 1998, when the GOP's James LaBelle unseated Chairman Robert L. Grever.
"I don't know how it's going to turn out," said Bob Cook, leader of the Lake County Republican organization. "I think it's going to be close."
In a telephone interview Thursday, Stolman said he was surprised by Lawlor's move to unseat him. Stolman said he had been planning to mentor Lawlor as the board's vice chairman until he learned of Lawlor's plans.
"It certainly came out of the blue for me," said Stolman, of Buffalo Grove.
Lawlor did not respond to multiple interview requests.
The board's members pick their own leader every two years, and that selection has been unanimous since 2000.
Suzi Schmidt held the post from 2000 to 2010, and Stolman was elected to his first term in 2010.
The GOP has maintained a majority on the board since its inception in the 19th century, so it's never been led by a Democrat.
As a result of this month's election, the GOP will hold a 13-8 majority once the new members are sworn in Monday.
The board was reduced from 23 members to 21, following a 2011 decision by the panel to redraw its districts.
A majority of at least 11 votes are needed to win the chairmanship.
At 29, Lawlor is the board's youngest member. The Vernon Hills resident was appointed to fill a vacancy in 2009 and won election to his first full term in 2010.
He won re-election this month.
Before joining the county board, Lawlor was a member of the Cook Memorial Public Library board and was that panel's president from 2005 to 2009.
Lawlor also worked on then-Rep. Mark Kirk's staff for a time.
County Commissioner Steve Carlson is supporting Lawlor, and he believes Lawlor has the votes to win.
"He'll bring a whole new approach," said Carlson, a Gurnee Republican. "He represents a new generation."
Grayslake Democrat Pat Carey is backing Lawlor, too. She said she's lined up with Lawlor on several issues, including environmental protection and gambling opposition, and she agreed to support Lawlor's bid when he asked.
"We tend to work very well together, and I think he'll be a good chair," Carey said.
Antioch Republican Linda Pedersen is in Lawlor's camp, too. Lawlor's youth isn't an issue for her.
"I see how hard he works," Pedersen said. "I see how knowledgeable he is."
Stolman, 64, has been on the board since 1992 and is one of the board's longest-serving members. He succeeded Schmidt as the board's leader when she left to serve in the state Senate.
Previously, Stolman had served as the board's vice chairman for two years.
Stolman touted his work to keep the county's budget balanced among his accomplishments as chairman. Stolman also pointed to the resurrected plans to extend Route 53 into the Lake County, a proposal he has championed, as a strength.
"For the first time in decades, this project is close to being a reality," he said.
In light of Lawlor's challenge, Stolman said he's been trying to build support among the board's members.
"The question is, if things are going great, why would you want to change horses midstream?" he asked.
Zion Republican Brent Paxton is supporting Stolman. Paxton said he pledged his vote before Lawlor made his candidacy known and will stand by his word.
Waukegan Democrat Mary Ross Cunningham said she is leaning toward supporting Stolman but hasn't made up her mind.
"I like both guys," she said.
The GOP's Cook didn't want to pick a favorite in the showdown, saying he likes Stolman and Lawlor.
"I will be interested to see how this turns out come Monday," Cook said.
Monday's meeting is scheduled for 9 a.m. at the county government center in downtown Waukegan. All 21 members will be sworn in at the start of the session.
After selecting a chairman, the board will choose a vice chairman, too.
Following that session, the Lake County Forest Preserve District board -- consisting of the same 21 members -- will convene to choose a president and a vice president.
Lincolnshire Republican Ann Maine has been the forest board's leader since 2010 and is expected to retain that post.