SPRINGFIELD -- On a day set aside to rev up the party faithful, Illinois Republicans instead found themselves grappling with their own internal shake-up.

Andrew McKenna, chairman of Illinois Republican Party for nearly five years, surprised his colleagues Thursday by resigning the top post just hours before a major GOP rally at the Illinois State Fair.

Party leaders quickly named Pat Brady, a former Bloomington resident and Illinois' representative on the Republican National Committee, to guide the party through what is shaping up to be a contentious and competitive primary election season.

McKenna said he stepped down because he wasn't going to seek re-election next April and wanted to give party officials an opportunity to have a new chairman in place before the election season begins to heat up.

"It just became clear to me if I wasn't going to run for re-election, that this is a better time to transition," McKenna said.

McKenna's exit moved the spotlight away from many of the candidates for statewide posts who were hoping to use the day to begin setting themselves apart from their competition.

State Sen. Bill Brady of Bloomington, who is making his second bid to become the chief executive, argued that voters want a "real Republican" in the Governor's Mansion. He is among at least six GOP candidates for governor.

State Sen. Matt Murphy, R-Palatine, launched the first television ad of the election season, taking aim at state Sen. Kirk Dillard of Hinsdale, who also wants the top spot.

U.S. Rep. Mark Kirk, the presumptive Republican front-runner for the U.S. Senate seat now held by Roland Burris, talked at length about his experience as a congressman representing the Chicago's northern suburbs.

One of Kirk's handful of challengers, former circuit judge Donald Lowery of Golconda, told party officials that he has been a prosecutor and a judge and is now ready to bring that experience to the legislative branch.

"I'm kind of your total package," Lowery said.

Also working the crowd was state Sen. Dan Rutherford of Chenoa, who is running for state treasurer. He is in a rare position among Republicans seeking statewide office: For now, he has no competition.

Won't hinder the party?

Most candidates said the leadership shuffle wouldn't hinder the party as it tries to chip away at Democratic dominance in state government.

Carbondale Mayor Brad Cole, one of at least three GOP candidates for lieutenant governor, said the switch would give the party continuous leadership throughout the election season.

"It will give us a single voice to win in November," Cole said.

Former state treasurer Judy Baar Topinka, who is mulling a political comeback, brushed off concerns about the timing of McKenna's announcement.

"Whatever fits his life. He has the right to make that decision. There have chairmen before. There will be chairmen after," said Topinka, a possible candidate for comptroller.

Said Pat Brady, "It's August. If you're going to make the switch, this is a good time to do it."