Republicans are trying to avoid becoming their own worst enemy again in a U.S. Senate contest, this time in Georgia.

Representative Paul Broun has called evolution and the Big Bang theory “lies straight from the pit of hell” and is holding a drawing for a semi-automatic assault rifle. He's among seven Republicans competing to face a presumed Democratic nominee with a rich political pedigree: Michelle Nunn.

Broun's backing from a segment of the Tea Party movement has some Republicans worried that he could alienate independent voters, which would put them at a disadvantage in the general election and open the door to a Democratic pickup of the seat.

“Michelle Nunn’s success is totally dependent on whether the Republicans fumble the ball,” said Rusty Paul, a former state senator and party chairman who is backing one of Broun’s opponents, fellow U.S. Representative Jack Kingston. “Somebody like Paul Broun is maybe too far right.”

The fractures that have plagued Republicans for the past two election cycles are on full display in Georgia, where a loss of retiring Senator Saxby Chambliss' seat would make the party's bid to win the net six seats needed to take control of the chamber that much more difficult.

No front-runner

No clear front-runner has emerged, and the May 20 contest probably will go to a July 22 runoff, meaning the party would have just three-and-a-half months before the general election to campaign for the eventual nominee. One recent poll showed Representative Phil Gingrey with a slight edge, though no candidate registered more than 20 percent support from likely Republican primary voters.

At the national level, Republicans want to avoid a replay of the intra-party strife that led to the nomination of unsuccessful 2012 Republican Senate candidates Todd Akin in Missouri and Richard Mourdock in Indiana.

“Republicans need to hold Georgia in order to make their path to the majority easier,” said Nathan Gonzales, deputy editor of the Rothenberg Political Report. “There are some Republican fears that if their nominee is too polarizing, it could jeopardize their ability to hold the seat.”

At a barbecue his campaign held for supporters before a Feb. 22 debate in Gainesville, Georgia, about 50 miles northeast of Atlanta, Broun declared himself the strongest candidate to run against Nunn.

‘Will win’

“The only way a Democrat is going to have any chance to win this race, in my opinion, is if we nominate a big- government, big spending, go-along-get-along, establishment type of Republican,” Broun, 67, a physician and Navy reservist who served in Afghanistan, said in an interview at the event. “Once I am nominated, I will win the general election.”

Standing on the bed of a white pickup truck, Broun, who supports abolishing the Environmental Protection Agency and the Department of Education, likened the federal government to a dragon and pledged to “put it back in its cage.”

“The cage bars are the enumerated powers of the Constitution, and I will not rest until we put that dragon back in the cage where it belongs — forever,” he said to cheers and applause.

Broun today released his first television ad of the campaign, in which he asserted that Democrats “fear” him because he’s “the strongest conservative” in the race.

Tea Party

Broun and Gingrey are vying for the backing of groups aligned with the small-government, Tea Party wing of the party. Kingston’s base of support is the business community, while two other contenders — former Georgia Secretary of State Karen Handel and David Perdue, former chief executive of Dollar General Corp. and Reebok International Ltd — are campaigning as Washington outsiders. Minister Derrick Grayson and attorney Art Gardner also are running.

Gingrey, an obstetrician, said last month that Akin was “partially right” when he said in August 2012 that “legitimate rape” rarely results in pregnancy.

“I’ve delivered lots of babies, and I know about these things,” Gingrey, 71, said at the time, adding that he advises patients to “just relax” because stress can impede conception. “But the fact that a woman may have already ovulated 12 hours before she is raped, you’re not going to prevent a pregnancy there by a woman’s body shutting anything down because the horse has already left the barn, so to speak.”

Party leaders

Akin's remark prompted party leaders to withdraw their support for his candidacy and effectively killed his bid to unseat Democrat Claire McCaskill. In Indiana, Republican Senate candidate Richard Mourdock lost in 2012 to Democrat Joe Donnelly after Mourdock defeated six-term Senator Richard Lugar in that state's primary.

Of the three sitting congressmen in the race, Broun has garnered the highest marks from the Club for Growth, a Washington group that promotes small government. Broun has a 99 percent lifetime approval rating from the group, whose president Chris Chocola said yesterday that America would be a better place if there were “more pro-economic-growth fighters like Paul Broun serving in Congress.”

Kingston, who as of Dec. 31 had raised more money than any other candidate in the race including Nunn, said in an interview after the debate that he was in a strong position.

“We’re raising the resources that we need to get the message out,” he said, adding that he was the “most conservative” candidate in the contest, “who has been able to get some things done” in Washington.

Conservative ranking

During the Feb. 22 debate, on his website and in the interview, Kingston touted a National Journal ranking designating him the 17th most conservative U.S. House member, ahead of Broun or Gingrey.

Kingston, 58, raised $4.2 million and had $3.4 million cash on hand as of Dec. 31. Nunn had raised $3.3 million and had $2.5 million in cash on hand, according to the Center for Responsive Politics, a Washington group that tracks campaign spending.

Perdue had raised $2.6 million and had $1.8 million in cash on hand as of year’s end, while Gingrey and Broun had raised $1.5 million and $1.2 million respectively, according to the group. Gingrey, who carried over unspent money from past House races, had $2.4 million in cash on hand, compared with about $190,000 for Broun.

Prominent Democrats, including Senate Majority Leader Harry Reid of Nevada, are among Nunn's contributors, as are billionaires Warren Buffett and Michael Bloomberg, the founder and majority owner of Bloomberg News's parent company, Bloomberg LP.

Nunn support

Georgia business leaders with a record of backing Republicans have been writing checks to Nunn. They include John Wieland, founder of John Wieland Homes and Neighborhoods Inc.; Jim Cox Kennedy, the chairman of Atlanta-based communications company Cox Enterprises Inc.; and Tom Cousins, a developer who helped shape downtown Atlanta in the 1970s and 1980s.

Nunn, 47, also could benefit from family ties: She’s the daughter of former U.S. Senator Sam Nunn. Still, a Democratic victory will be tough in a state that 2012 Republican presidential nominee Mitt Romney won by eight percentage points.

“Even though Republicans have sort of a messy primary, a lot of things need to fall Democrats' way in order for Nunn to win,” Gonzales said. “Georgia fundamentally still leans Republican in federal races, and this is shaping up to be a difficult cycle for President Obama and his party.”

Republicans point out that Nunn is an untested candidate.

‘Political lineage’

“She certainly has great political lineage, but she’s never run for office,” said Whit Ayres, a polling expert who advises Handel.

Still, on the Republican side, “there are clearly some candidates in the race who would put the seat in jeopardy if they won the nomination,” Ayres said.

The National Republican Senatorial Committee, the Senate Republicans' campaign arm, hasn't endorsed a candidate in the contest.

“There’s a strong field of candidates that represent Georgian values and ultimately voters will decide the candidate they believe best reflects their voice,” NRSC spokeswoman Brook Hougesen said in an email.

For her part, “Michelle Nunn’s hoping for Broun,” said Merle Black, a political science professor at Emory University in Atlanta. “I have a hard time thinking he could win a statewide race in Georgia.”

--With assistance from Laura Litvan in Washington.