Party Chairman Robert Peickert is collecting signatures to be named on the DuPage County ballot as opponent to the two-term incumbent.
He is required to obtain 998 signatures before the June 2 deadline, according to the DuPage County Election Commission, although he said he was hoping for at least 2,500.
No candidates presented themselves during the party's recruitment process for the primary elections in March, Peickert said. He was approached by a number of people who asked him to pursue party nomination to ensure there were as many Democratic challengers as possible, he said.
"We needed to have Democrats on the ballot to give voters an option, and I felt there were some issues that needed to be addressed," he said. "I'm hoping to add some county issues that I think the voters need to hear about."
Cronin said he didn't expect to run unopposed and "welcome(d) the discussion and the political process."
He said he was confident his record would continue to resonate with voters.
"I've been through this before," said Cronin, who also served in the Illinois state senate. "I feel good about what we've been doing at the county. We've made some major strides in reform and reduced the size, scope and cost of local government and we have a proud record of accomplishment."
Peickert said his party is working to find challengers for other unopposed County Board seats. While the party is still looking for a candidate for the second district, Regina Brent and Rolly Waller are collecting signatures for districts 1 and 5, respectively.
Republican board members Paul Fichtner of District 1, Pete DiCianni of District 2 and Tonia Khouri of District 5 are all up for reelection in November.