Businessman David Perdue stunned Georgia’s Republican political establishment Tuesday by capturing the party’s U.S. Senate nomination in his first run for office.

The former CEO of Reebok and Dollar General toppled 11-term U.S. Rep. Jack Kingston by a narrow margin, setting up a battle in the fall of political newcomers with famous kin. Perdue’s cousin Sonny was a two-term governor, and Democrat Michelle Nunn’s father, Sam, was a four-term U.S. senator.

In his victory speech, Perdue made clear he would tie Nunn to President Barack Obama’s administration.

“It’s about the failed administration of which she’s going to be a supporter,” he said in a post-election interview. “My point now is about making her defend the party that she is now supporting.“

In addition to his famous last name and lingering political network from his cousin, Perdue deployed $3 million of his own money to back his bid. Still, he was outspent by Kingston and allied Super PACs — including the deep-pocketed U.S. Chamber of Commerce.

While Kingston held onto his big margins in South Georgia, Perdue more than wiped him out with big showings in populous metro Atlanta.

Perdue now faces Nunn, who has amassed a considerable bankroll and is leading in some early polls. The strength and crossover appeal of the CEO of nonprofit Points of Light — not to mention the scars of a bloody, nine-week GOP runoff — have Democrats convinced they could break Republicans’ hold on the state.

“There is a clear contrast in this race between Michelle Nunn, a leader who has spent the last 25 years leading volunteer organizations and lifting communities up, and David Perdue, someone who has spent his career enriching himself while oftentimes tearing companies and communities apart,” Georgia Democratic Party Chairman DuBose Porter said in a statement. “Georgians want leaders who will fix the mess in Washington, not someone who puts personal profit ahead of regular people.”

Republican U.S. Sen. Saxby Chambliss set off a free-for-all in January 2013 when he announced he would not seek re-election. Seven Republicans, including three U.S. House members who will now be leaving Congress, jumped into the race ahead of the May primary. Perdue won that contest with 30 percent of the vote — well short of the 50 percent required to move on.

Kingston edged former Georgia Secretary of State Karen Handel to gain the second runoff spot on the strength of a fundraising advantage and huge margins in areas he represented in South Georgia.

In the runoff, the state’s political establishment, as well as many tea party leaders, coalesced behind Kingston. Handel backed him, along with all of the Georgia U.S. House Republican delegation and much of the General Assembly. But Perdue continued to hammer away on Kingston as a Washington insider who has been in the game too long.

In addition, an Atlanta Journal-Constitution investigation found that a Palestinian national named Khalid Satary might have funneled at least $80,000 in illegal straw donations to the Kingston campaign and his campaign was warned of the problems by a Republican attorney long before the candidate returned the money. The FBI is investigating Satary but not Kingston.

The congressman painted Perdue as a risky unknown whose successes as a CEO were marred by presiding over the largest textile bankruptcy in history at Pillowtex. Kingston has also said Perdue benefited from a "sweetheart" appointment to the Georgia Ports Authority by his cousin, then-Gov. Sonny Perdue. An AJC investigation found that a trucking company owned by the Perdues hauled cargo from the Savannah Port while David Perdue was on the board.

The brutal nine-week period has led to calls from a growing number of GOP officials to shorten the cycle or do away with a federal runoff altogether. Minutes before the polls closed, Sonny Perdue said the party should establish “ground rules” to avoid giving Democrats an advantage.

Handel acknowledged that the nine-week runoff was painful, but she said such contests always turned negative and runoffs should not be abandoned.

“Do we really want our nominee to be someone who won 30 percent of the vote?” she said.

The insider-vs.-outsider theme that marked most of the run-up to the primary continued through the past nine weeks.

“I think Jack Kingston has been there for 20-something years and he hasn’t fixed it yet, so now he’s going to fix something?” Kay Bragg said as she voted in Atlanta’s Morningside neighborhood. “I just think that they’ve all been in there too long. We need term limits and we’ve never had them.”

Debby Torak, one of a handful of voters casting ballots at a quiet Gwinnett County precinct, said Kingston’s establishment credentials won her support.

“I think he has the experience and I’ve just heard a lot of good things about him,” Torak said. “And not so many things about David Perdue.”

Heavy runoff spending depleted the candidates’ coffers. But the Republican fundraising machine is already gearing up to support Perdue in the general election. Longtime GOP fundraiser Eric Tanenblatt plans an Aug. 20 event for national Republican organizations to back the nominee this fall.

Tanenblatt said both Kingston and Perdue had committed to attending before Tuesday’s outcome, and both sitting senators are behind the effort. Chambliss has kept a low profile throughout the primary process, but he praised Perdue as soon as the race was called Tuesday.

“Georgia deserves a representative who will work to solve our fiscal crisis and put our country back on track,” Chambliss said in a prepared statement. “Now that the primary is over, I urge all Republicans to unite behind David Perdue. In order for Congress to stop President Obama’s power grab and fix our country’s most pressing issues, we must fire Harry Reid and return the Senate to Republican control.”

Kingston, for his part, said he immediately pledged his support in a concession call to Perdue and told him “once we combine our two camps we will absolutely be unstoppable.”

As for why he fell short, Kingston said he was unable to shake the Washington insider label.

“People are very frustrated with Washington, D.C., and I think that was a big hurdle,” Kingston said. “And my opponent capitalized on that — as he should.”