Republican state Rep. Mike Bost will announce on Monday that he is challenging freshman Rep. Bill Enyart, D-Ill.,  in one of the state’s most competitive districts.

Bost’s campaign confirmed to CQ Roll Call that he will make his announcement at a series of stops throughout the 12th District, located in the southwest corner of the state.

“I’m very frustrated,” Bost said in a phone interview. “I feel like what has happened in Chicago that has caused us so much trouble statewide has moved to D.C. So I feel like I’ve got to do this.”

In 2012, Enyart won this district by 9 points over businessman Jason Plummer, a former candidate for lieutenant governor whom GOP operatives privately described as a lackluster candidate. Meanwhile, President Barack Obama carried the district by 2 points that year.

Republican operatives argue Bost, a former Marine Corps corporal who has served in the state House since 1995, has a better shot in 2014.

The 12th District is rated a Democrat Favored contest by Rothenberg Political Report/Roll Call.