Illinois Rep. Mike Bost received a fourth Democratic challenger Wednesday as St. Clair County State Attorney Brendan Kelly announced his candidacy for the state’s 12th Congressional District.

Bost first won his seat in 2014, beating incumbent William Enyart. He won re-election last year with 54 percent of the vote.

The seat was also previously held by longtime former Democratic Rep. Jerry Costello and Kelly said he has sought Costello’s counsel.

Kelly’s ties run deep in the district, having first moved there when his father was stationed at Scott Air Force Base, and he met his wife in the sixth grade in Wolf Branch, he told the Belleville News-Democrat.

“I think people know that I believe in public service as seen with my time with the Navy or my time as a prosecutor here in St. Clair County, trying to protect public safety,” he told the newspaper.

Kelly said he had been approached by family and friends about challenging Bost. “And if you can help your country, I think you have a duty to come forward and step up and serve where you think you might be able to help.”

Like many Democrats who have announced runs against incumbent Republicans in next year’s elections, Kelly pointed to Bost’s support of the Republican replacement of the 2010 health care law as a reason for running, saying it could lead 38,000 Southern Illinoisans losing coverage, including 7,000 veterans.

But Kelly would be joining a crowded Democratic primary, with four other candidates having already announced.

George O’Connor, Bost’s spokesman, said he would wait for Democrats to finish their “unsettled nominating process” before commenting.

“Regardless of who they select, their nominee will have a difficult time justifying lockstep support for Nancy Pelosi’s extreme agenda in Washington,” O’Connor said