Martin's says his opponent Attorney General Chris Koster (D) did not accept the invitation to appear at the townhall forum hosted by the Leaders Lead Locally Institute.
"I'm what I call a constitutional conservative," says Martin. "Somebody who believes we have certain rules we have to live by. And within that framework, there's a lot we can do together. But we have to protect our rights and I believe the attorney general in Missouri has a role in that."
Martin picked up some key endorsements in recent days from former attorneys general John Aschcroft and John Danforth.
Chris Koster just won the endorsement of the National Riffle Association. He's the only Democrat in Missouri to get a nod from the NRA.