Doug Truax is a West Point graduate and retired Army Ranger who believes he is the kind of conservative candidate Illinois Republicans need to beat incumbent Democrat Dick Durbin in the fall election.
"The question is who's the best candidate to go against Durbin," Doug Truax said. "We need to put up a new face with new ideas to go after Durbin and I think that's what's happening."
Illinois Senator Jim Oberweis, 67 -- who's run for the U.S. Senate, Congress and governor before -- said he's got the experience needed to beat Durbin.
"I made mistakes. Hopefully I've learned from those mistakes and will do a better job," Oberweis said.
Truax argues it's the "electability issue."
"It's what it comes down to now. It's like I said, you lose five races in 11 years and you get your negatives up."
Oberweis said he's got name recognition.
"I have 75% statewide name recognition. I have 88% name recognition among Republicans and it's generally quite favorable."
In a video released Wednesday, former U.S. House Speaker Newt Gingrich endorsed Truax, saying, "I believe Doug Truax is the person who can win the Senate seat and get the job done."
Truax, 43, said in his opinion Oberweis is prone to mistakes on the campaign trail that could embarrass the party's entire ticket.
"He's a gaffe machine. He's a good man but we've seen this before and it's happening again," Truax said.
"It's more likely to be somebody who's less experienced to make that kind of mistake than somebody who's more experienced," Oberweis said.