The question is whether a bruising party primary becomes a liability, particularly if voters nominate U.S. Rep. Paul Broun, who once called evolution and the Big Bang Theory "lies straight from the pit of hell.''
Broun and U.S. Rep. Phil Gingrey, both conservative physicians, are the only Republicans to announce officially since incumbent Saxby Chambliss said he will retire. But the GOP primary field eventually could include as many as a half-dozen candidates with a credible shot at a runoff spot.
Broun, whose district includes the University of Georgia in Athens, drew national headlines last year for that science commentary he delivered at a church. He's flouted GOP leaders on recent fiscal votes, saying the party's position wasn't conservative enough.
In a recent fundraising letter, he boasted that he was the first member of Congress to call Obama "a socialist who embraces Marxist-Leninist policies.''
That makes Broun a tea party and evangelical favorite. To other Republicans, however, such comments stir memories of 2012 losses in Senate races in Missouri and Indiana where the GOP nominees, Todd Akin and Richard Mourdock, made controversial comments about women, rape and abortion.
"There's no question that the Republican Party in Georgia and the nation are concerned that we could have another Todd Akin-type scenario here,'' said Heath Garrett, a Republican campaign consultant and former top aide to Georgia Sen. Johnny Isakson.
Democrats control 55 seats in the Senate, and Republicans would need to hang on to the ones they control now and pick up six more next year to take control for the first time since 2006.
At least one more Georgia congressman is likely to jump in, and a trio of Washington outsiders is considering the race: a wealthy Atlanta businesswoman who helped bankroll a Mitt Romney's presidential campaign; the former Susan G. Komen Foundation executive who took on Planned Parenthood; and the cousin of former Gov. Sonny Perdue.
"It's going to be a free-for-all with a lot of dominoes,'' said Sue Everhart, the head of the state GOP.
Isakson says he's neutral in the primary.
National conservative groups Freedom Works and Club for Growth, which have helped tea party candidates such as Texas Sen. Ted Cruz win high-profile races, say many candidates have talked to them about support. For now, both groups say they're watching the field develop. It would be a blow to Broun if he can't harness the support of either.
Democrats believe they can tap into the Missouri-Indiana playbook, particularly if U.S. Rep. John Barrow, a moderate from Augusta, runs. Barrow has survived consecutive elections as one of national Republicans' top House targets.
The state Democratic chairman, Mike Berlon, said Barrow has detractors among core Democrats for his vote against Obama's health care law, but said he'd expect enthusiasm at any opportunity to win back Chambliss's seat.
Berlon said the congressman is an ideal candidate to assemble a majority coalition of African-Americans, white urban liberals, suburban moderates and just enough rural conservatives. "We're already close,'' he said, noting that Obama got 47 percent in 2008 and 45.5 percent in 2012 "without the national party lifting a finger.''
Garrett said that "if the Republican nominee scares suburban whites, John Barrow becomes a very formidable candidate.''
Barrow has held meetings with major Democratic donors in Georgia and talked with the Democratic Senatorial Campaign Committee leaders, but has not announced his intentions.
The only other Democrat making strong overtures is Michelle Nunn, a not-for-profit executive who's the daughter of former Sen. Sam Nunn, D-Ga.
Berlon said he expects Nunn and Barrow to meet soon to "talk about who's going to run.''
On the Republican side, Rep. Jack Kingston of Savannah is expected to enter the race soon. He raised $843,000 in the first three months of the year, about 10 times what he collected during the same span two years ago when he was preparing only for an easy re-election to his 11th term.
Rep. Tom Price, vice chairman of the House Budget Committee, has said he won't make a move until after Congress passes a budget. But he's also got to consider that many high-profile GOP donors and strategists are lining up behind Gingrey or Kingston.
The longer Price waits, the more likely it is that Karen Handel, a former Georgia secretary of state, will run. The two are close friends.
After losing the 2010 Republican primary runoff for governor, Handel worked for the Susan G. Komen Foundation. She resigned amid controversy over her push to dissociate the organization from Planned Parenthood, a provider of women's health care and abortion services.
Two electoral newcomers would bring their personal wealth to the campaign.
Businessman David Perdue also has name ID as the cousin of a popular former governor.
Kelly Loeffler is a co-owner of the Atlanta-based company that recently bought the New York Stock Exchange and Atlanta's professional women's basketball team. She's never run for office, but is one of the top fundraisers for Romney last year and has been increasingly active in Georgia Republican political circles.
Chip Lake, a paid strategist for Gingrey, said the uncertainty makes it difficult to handicap the race.
Against Broun alone, Gingrey is a mainstream social and fiscal conservative, but he also caught heat earlier this year when he defended Akin.
Gingrey apologized, calling his own remarks "stupid.'' In a three-man race, Kingston becomes a favorite of many Chamber of Commerce Republicans. But Kingston also is from south Georgia, far from the population center of Atlanta, where Gingrey has won elections for decades.
Broun has just $217,000 in his campaign account, about one-tenth of his House rivals and not enough for one week of television ads in Atlanta. But he's also got a strong grass-roots following.
Handel can capitalize on experience in government, while still being an outsider to an unpopular Congress. She could be a particularly strong candidate if she's the only woman in the race.
But Loeffler could neutralize any gender advantage. Handel can use the Planned Parenthood flap to boost her conservative credentials, but she's had run-ins with staunch anti-abortion groups because she supports policy exceptions for rape, incest and to allow for in-vitro fertilization.
Loeffler can sell her success story and roots on an Illinois farm. But she'd still have to introduce herself to small town and rural Georgia as a millionaire from Atlanta.