Michelle Nunn just raised the stakes in Georgia's Senate Republican primary.

In announcing a Senate campaign that had been expected for weeks, the Democrat with a well-known last name gave her party a credible contender who could make the general election interesting if Republicans botch a race that tilts in their favor right now.

Nunn is the latest entrant into a complex national battle for control of the Senate. Republicans are expected to have to net six seats in 2014 to win back the majority. Georgia and Kentucky represent the only two realistic pickup opportunities for Democrats at this point, though both contests look like pretty tall orders for the party. But if they can steal away even one, it will make life awfully difficult for Senate Republicans.

And that's where Nunn, 46, comes in. The head of a nonprofit group that encourages volunteerism, she is the daughter of former senator Sam Nunn, a centrist Democrat who represented the Peach State in the upper chamber for nearly a quarter century. The younger Nunn is a political newcomer who faces trial by fire: Trying to win a Senate race in a state Republicans have dominated in recent years.

"I'm running for Senate because I believe that America's spirit of innovation and entrepreneurship, when unleashed, can create extraordinary possibilities," Nunn said in an e-mail to supporters on Tuesday. "We need to tap into the creativity of citizens and businesses to create jobs and a better future."

The Republican side of the race to replace retiring Sen. Saxby Chambliss (R-Ga.) is a potentially competitive contest. The field includes Reps. Paul Broun, Jack Kingston and Phil Gingrey, and former secretary of state Karen Handel.

Broun, in particular, could pose problems for Republicans in the general election. Controversial comments and strident conservatism could make him a shaky GOP nominee. Meanwhile, Gingrey has stoked controversy with a remark that former Missouri Senate nominee Todd Akin was "partly right" about rape. Gingrey later said his remark was misconstrued, as he clarified he was not defending defend Akin's comments about "legitimate rape" rarely causing pregnancy.

On the heels of a cycle in which controversial candidates like Akin and Richard Mourdock in Indiana cost Republicans Senate seats in red states, Republicans in Georgia are under extra pressure to nominate an electable contender.

"I don't think Nunn is ready for prime time, but Republicans must still be responsible and nominate a well-funded, reasonable candidate," said Joel McElhannon, a Republican strategist unaligned with any of the Senate candidates. "It is now very important that Georgia Republicans have a nominee who represents the best values of the Republican Party and has the resources for a tough runoff and general election campaign."

Democrats are already trying to stir the pot in the GOP primary, believing that if it produces a flawed nominee, Nunn will be well-positioned to pounce. In a fundraising e-mail for Nunn sent Tuesday, Sen. Kirsten Gillbrand (D-N.Y.) declared that "the alternative is disturbing."

Nunn's allies are hoping her nonpolitical background and her well-known last name will boost her ability to build a moderate statewide profile during the next few months. Unlike her father, who cut his political teeth early in the state legislature, Nunn hasn't waded heavily into the political arena in her career.

She currently serves as the CEO of Points of Light, a group that encourages volunteer efforts. The organization formed out of the 2007 merger of HandsOn Network, a group that Nunn headed, and Points of Light Foundation, which was formed in 1990 in response to George H.W. Bush’s call for Americans to volunteer. Nunn flirted with a Senate bid before in 2004, but ultimately declined so she could focus on her family.

A Phi Beta Kappa graduate of the University of Virginia, Nunn has also studied overseas at Oxford University and in India.

Republicans, meanwhile, are already going after Nunn. They note conservative Democratic Rep. John Barrow already passed on the race. And they have sought to tie Nunn to President Obama and Democratic congressional leaders, noting that she was at a Democratic Senatorial Campaign Committee fundraiser with Obama in May. The National Republican Senatorial Committee has already begun decrying the "Obama/Nunn agenda." Given Georgia's red tilt, if they are successful, it could be a long campaign for the first-time candidate.

Demographic trends have given Democrats an extra reason to aim to be as competitive as possible in statewide elections. A surge in the minority population, which typically favors Democrats, has stoked optimism in the party about turning Georgia blue in the coming years. But with Republicans currently controlling all statewide offices, Democrats have a way to go, observers say. And 2014 may be too early to see any major shift.

"Right now, I think it's still a state where if the Republicans nominated a credible candidate, the Republican should be favored in the election in 2014," said Emory University political scientist Merle Black.