Updated on Friday, Nov. 11: Seth Lewis conceded the race to Tom Cullerton Thursday evening.

A west suburban state senate candidate has yet to concede, despite the race being called for his opponent.

Seth Lewis, R-Bartlett, is holding out hope because all mail-in ballots are not yet counted. The ballots must be post-marked by Nov. 8.

The race between Lewis and incumbent Tom Cullerton, D-Villa Park, was one of the most expensive campaigns for Springfield — and also one of the closest.

The district, just south of O’Hare International Airport, tends to run Republican, but the Associated Press called the race for Cullerton, who has 788 more votes with 86,492 ballots cast.

“It’s up to him if he wants to give me a call and (concede), that’s not up to me to make that call for him,” Cullerton said Thursday.

Derek Murphy, Lewis’ campaign manager, said Lewis has not conceded and they are still waiting for all the ballots to be counted.

“We do not have all the information from the respective county election commissions,” Murphy said in a statement. 

Democrats have a supermajority in the state Senate, though they lost their supermajority in the state House of Representatives.

Cullerton said he’s already anticipating another heated campaign for reelection in 2018.

Combined, the Lewis and Cullerton campaigns raised more than $3 million just in the last few months.

“I can’t imagine they would spend less next time,” Cullerton said.

Tony Arnold covers Illinois politics for WBEZ. Follow him @tonyjarnold.