Sensing ferment amongst conservatives, a former Bozeman lawmaker is launching a campaign against what he calls Montana’s “big-government Republicans.”

This is not the first time Roger Koopman, who represented southern Gallatin County in the Montana House of Representatives from 2005 to 2008, has publicly challenged fellow Republicans on their conservative credentials.

But Koopman said Thursday his latest effort, done under the banner of the newly formed Montana Conservative Alliance, aims to harness the energy of tea parties and other conservative movements that are “ready and anxious to help any principled conservative get elected.”

“Democrats don’t negotiate their basic principles, and Republicans, depending on the Republican, often do. The more liberal leaning Republicans do,” Koopman, executive director of the new group, said Thursday.

In a letter sent to Republican lawmakers, Koopman said his new group is “not a partisan or Republican organization,” but adds that its “chief focus at this time will be on the Republican primaries, since that’s where most or all conservatives will be found.”

In 2008, Koopman made a public plea to fellow conservatives to oust “socialist Republicans” from office, and singled out more than a dozen GOP lawmakers as too liberal. Many of the incumbents named by Koopman that time around wound up facing primary challengers, and three lost in the primary, including Bruce Malcolm in Park County. Malcolm was defeated by Rep. Joel Boniek, R-Livingston.

Asked if he had any Republicans in mind this time, Koopman named four: Rep. Llew Jones, R-Conrad; Rep. Duane Ankney, R-Colstrip; Rep. Jesse O’Hara, R-Great Falls; and Sen. Dave Lewis, R-Helena.

“I’m not surprised,” said Lewis when asked about the effort.

He said he had heard Koopman was driving to Helena Thursday night in hopes of recruiting a challenger.

Lewis described himself as a “pragmatic Republican.”

“I don’t believe in tax increases, I am strongly pro-life. … I got an ‘F’ from the MEA-MFT,” Lewis said, referring to the state teachers’ union. “If that doesn’t satisfy Roger, that’s fine.”

O’Hara was also defiant.

“If Koopman sees you go over to the opponents and try to work out something that works out for the both of us, he has a problem with that,” he said. “He thinks you don’t even visit with the other side, you don’t comprise…. I don’t think the voters send us over just to go head to head.”

Lewis did express fear that the race could turn nasty, citing a Republican primary in 2008 between Melville Republican Mike Miller and sitting Rep. John Ward, R-Helena, one of the lawmakers dubbed “socialist” by Koopman. In that race, fliers were sent to voters by a Bozeman-based group putting Ward’s photo beside pictures of serial killers.

“Let him take his best shot,” Lewis said. “I will work very hard. I get into campaigns. That’s for sure.”

Montana GOP chairman Will Deschamps said the party wouldn’t be wading into any primary battles.

“The party doesn’t anoint anyone. The anointing is done by the candidate and the voters,” he said.

He said primaries can “sharpen” candidates, and help them raise money. Still, he admitted that primary fights can get ugly.

“I suspect that when it comes to incumbents, it might get a little messier, but that’s our election process,” he said.

Daniel Person can be reached at dperson@dailychronicle.com or 582-2665.