The mailer is the work of Ute Pac, which was created by Dimitri Moumoulidis, who has been active in Democratic politics.
"My thinking is that I need to slow [Wimmer] down. He's been moving like a freight train pretty much unchecked and I don't want him walking away with 60 percent at convention," Moumoulidis said. "I want him to at least have a primary and there's a lot of stuff out there that's questionable with the guy. I'm really uncomfortable with him becoming our Congressman. He was one of the most extreme, radicalized far-right members of the entire Legislature."
The Wimmer campaign said it's not surprised someone is throwing mud at the campaign, but condemned the mail piece as a cheapshot.
"This is the same type of dirty politics from PACs that tried to stop Senator Mike Lee from winning in the last election and against candidates in this one," said Dan Hauser, Wimmers campaign chairman. "It didn't work then and it won't work now. The delegates are far too intelligent to fall for this type of campaign from some sort of faceless, shadowy PAC."
Hauser said the PAC is taking a shot at Wimmer because he is the one who can beat and will beat Democratic U.S. Rep. Jim Matheson in November.
Moumoulidis said that's not the case and he doesn't agree with Matheson on an array of issues.
"And, if I was looking out for Jim Matheson's interests, I wouldn't be going after Carl Wimmer, because Carl Wimmer is his best chance of winning," he said. "My focus is on what's in the best interest of the people of Utah."
Robert GehrkeTwitter: @RobertGehrke