Rep. Darin LaHood is considering and is open to a primary run for the U.S. Senate seat, according to a source with direct knowledge of the congressman’s thinking. The congressman has about $5.8 million cash on hand to help a potential bid.

Democratic U.S. Senator Dick Durbin will not seek reelection next year, he said on Wednesday, setting the stage for a competitive intra-party contest to fill his seat in the Democratic-leaning state of Illinois.

Behind-the-scenes jostling was already underway before Senate Minority Whip Dick Durbin announced that he would not seek a sixth term in the upper chamber. Now, the race to replace him is a full-on frenzy.