PERRY, Ga. — As a little girl, Michelle Nunn clutched her father’s hand as they strolled the pecan groves of the family’s 2,400-acre farm, a moment captured in a black-and-white photograph that Sam Nunn used to help win election to the Senate. It hangs in a Sam Nunn exhibit in this small city south of Macon, where the main thoroughfare is Sam Nunn Boulevard.
It all speaks to another era. Mr. Nunn, a Democrat, last appeared on a Georgia ballot in 1990, and Georgians have since fled his party. Now his daughter, a political novice who spent 25 years running an Atlanta-based nonprofit volunteer network, is hoping to capitalize on the family name to reverse Democrats’ long decline in the Deep South.
With $3.3 million in the bank, Ms. Nunn is the party’s best hope in an open race to replace Senator Saxby Chambliss, a Republican, who is retiring.
Her campaign will test whether the rapidly changing demographics of Georgia — where state elections data show that the white vote dropped to 61 percent of the total in 2012 from 75 percent in 2000 — have shifted enough to return a Democrat to Washington. And it will reveal how much legacy still matters in politics.
Republicans say the Nunn legacy is a distant memory, and in interviews both daughter and father conceded that the family name would get her only so far. At 47, the cautious and cerebral Ms. Nunn is every bit her father’s daughter, down to her owlish glasses and centrist message about curing dysfunction in Washington.
“A lot of Georgians come up to me and say how much admiration they have for him,” Ms. Nunn said after meeting with campaign volunteers. “No matter which way they’re voting, they always consider themselves politically Sam Nunn Democrats. So it gets me a hearing for sure.”
In Washington, it also opens doors. Mr. Nunn, 75, who was the chairman of the Armed Services Committee, is a durable figure in the capital, where he runs an institute devoted to eliminating nuclear weapons. He confesses to “mixed feelings” at seeing his eldest child enter politics, but he has plunged in to help.
When Vernon E. Jordan Jr., the Washington power lawyer, hosted a fund-raiser for Ms. Nunn, her father introduced her. When Ms. Nunn hosted a breakfast for military industry and policy analysts, a former aide to her father helped draft the guest list. “It was like an old reunion,” Mr. Nunn said.
Two of his closest Republican friends, former Senators John W. Warner of Virginia and Richard G. Lugar of Indiana, are now donors to Ms. Nunn. Mr. Warner attended the breakfast, he said, and walked away impressed. So did Mr. Nunn; watching his daughter tackle military policy questions changed his view of her race.
“That morning,” he said, “was when I said to myself, ‘Hey, she’s got as good a shot as anybody in this race, maybe better.’ ”
Georgia has changed significantly since Mr. Nunn left office in 1997. The population has boomed as African-Americans have moved in and the Latino and Asian populations have risen. Between 1990 and 2010, nearly two million more people moved into Georgia than left it, according to demographers at the University of Georgia’s Carl Vinson Institute of Government.
As a result, the electorate has shifted north, toward racially diverse Atlanta and some heavily Republican suburbs and exurbs and away from small white cities in middle Georgia like Perry.
Democrats say they hope to leverage increased black turnout. In 2012, blacks accounted for 29.9 percent of voters, up from 21.2 percent in 1996, according to Georgia’s secretary of state, though part of that rise is attributed to Barack Obama’s presence on the ballot.
Ms. Nunn is courting them. On Monday, she marked Martin Luther King’s Birthday with Representative John Lewis, the Georgia Democrat and civil rights leader, who supports her.
If Ms. Nunn has a path to victory, Democratic strategists say, it will be by increasing minority turnout while attracting independent-minded whites, especially young voters and women. Democrats hope that a potentially fractious Republican primary, with eight candidates, will produce a far-right opponent whom Ms. Nunn could defeat.
“It’s a tough race, but she can win it,” said Roy E. Barnes, Georgia’s most recent Democratic governor, who lost a re-election bid in 2002.
But as a moderate in a midterm election, Ms. Nunn may have trouble exciting black voters. One of her Democratic rivals, Steen Miles, a black former Georgia state senator, said Ms. Nunn was “pandering too far to the right.” Other Democrats, including a psychiatrist born in Yugoslavia, Branko Radulovacki, who calls himself Dr. Rad, are also challenging Ms. Nunn.
Republicans, who suspect that Ms. Nunn is more liberal than her father, say the changes in Georgia have not happened fast enough to help her.
“Are the demographics in this state changing? Of course they are,” said Chip Lake, a Republican strategist. “Will the state become competitive soon? It absolutely will. But I don’t know that Michelle Nunn is going to be the candidate who helps the Democratic Party drive and develop that narrative and competitiveness.”
Here in Perry, where Ms. Nunn had her first political experience handing out fliers in 1972 in front of a Piggly Wiggly store, her challenge becomes clear.
Nunns are woven into the fabric of Perry. Ms. Nunn’s grandfather served as mayor; her father’s boyhood home is a local landmark. The family farmhouse, a wooden A-frame at the end of a long dirt road, past a stand of loblolly pines, remains a retreat for Mr. Nunn and his wife, Colleen, a onetime C.I.A. operative.
“I know the Nunns; they’re fine people,” said Larry Walker, a former Democratic leader of the Georgia House, who does legal work for the former senator. Yet Mr. Walker, whose politics now tilt Republican, is neutral so far.
Ms. Nunn is not Georgia’s only legacy Democrat. Jason Carter, a grandson of former President Jimmy Carter, is trying to unseat Gov. Nathan Deal. Mr. Walker is skeptical. “Political legacies don’t last like they used to,” he said.
In downtown Perry, where the main street is dotted with boutiques and cafes, older people nod at Sam Nunn’s name. Younger people, like Olivia Cranford, 18, a college freshman and coffee shop counter clerk, offer quizzical looks.
“Isn’t that a boulevard?” Ms. Cranford asked.
Ms. Nunn left Perry when she was 6, moving “against my will,” she quipped, to Bethesda, Md. She played basketball at the private all-girls National Cathedral School in Washington, and later trounced colleagues during late-night Nerf ball games. (“I am a very fierce competitive Nerf ball player,” Ms. Nunn said.)
But with her father, she said, constantly reminding her that “you’re from Georgia,” Ms. Nunn settled in Atlanta in 1989. Some socially conscious young professionals who had founded a group, Hands On Atlanta, to foster community service hired her to run it.
Over time, she built it into a national network that eventually merged with Points of Light, the organization inspired by former President George Bush, with whom she is close. She stepped down as chief executive in July to announce her candidacy.
Democrats in Georgia and Washington had been urging Ms. Nunn to run for years. With her children now 9 and 11 — her husband, who has a background in real estate, stays at home with them — she said the timing felt right.
On the campaign trail, Ms. Nunn plays it safe. She has distanced herself from Mr. Obama on his health care law by calling for a one-year delay in the mandate requiring most Americans to buy insurance, and her stance on same-sex marriage is nuanced. She supports it personally, but believes it should be left to the states, she said.
At the University of Georgia last week, she unveiled a “good government” plan featuring a lifetime ban on lobbying by members of Congress, and pledged to “restore civility” to Washington.
But Ms. Nunn will be able to take the high road for only so long. “She’s never been in a competition where she has had to stake out positions,” said Merle Black, a political scientist at Emory University in Atlanta.
Republicans are combing Ms. Nunn’s record for tidbits, like job cuts during the Points of Light merger. (“Layoffs for Cash,” their opposition research declares.)
“We are all girding ourselves,” said Elise Eplan, a co-founder of Hands On Atlanta and a close friend.
Ms. Nunn and her parents insist that she has what it takes. Here in Perry, where Mr. Nunn defied the odds in 1972, Mr. Walker, the former legislator, cautioned against underestimating her ambition and drive.
“She’s a Nunn,” Mr. Walker said.