Deal appealed to much of the state Republican Party's conservative base, winning the endorsement of the anti-abortion group Georgia Right to Life and counting among his backers much of the GOP legislative caucus and nearly all of the state's Republicans in Congress.
Handel ran an aggressive runoff campaign that slammed Deal as a relic and a corrupt insider politician. She hinted that the 67-year-old former congressman was too old, and when he complained about her negativity, Handel told him to put on his "big boy pants."
Jean Howard of Winder said she decided to vote for Deal on Tuesday based in part on Handel's tone.
"She just really came across as more negative than having a positive agenda," Howard said.
There is a message there, too, for Deal in the general election, Howard said. He must learn from his opponents' mistakes.
"I just don't like negative campaigning," she said. "If you don't have something positive to say, then don't bother to point your finger at somebody else. Get on your own platform. Have your own program. Don't come to the voters with all this negative stuff about other people."
Haynes Harold of Marietta said she wasn't crazy about Deal or Handel. But she chose Deal.
"There has been so much mudslinging," she said. "It's just awful."
Deal must now avoid turning off voters such as Jackson Williamson of Rome, who considers himself an independent. Independent voters in Georgia tend to lean conservative and are capable of swinging a general election.
As of now, after the bruising GOP primary and runoff, Williamson said he will likely back Barnes. He is turned off by how quickly Deal and Handel tried to erase the memories of the past few weeks.
"I hate to see negativity in any campaign, but doubly so when it becomes hypocritical -- they spend the whole campaign trash-talking the entire primary, and as soon as it's decided they throw their whole weight behind the winner," he said.
Still, given the evidence, blaming Handel's collapse on running a negative campaign is probably too simplistic an explanation.
Deal won by making huge gains in metro Atlanta over his primary performance. He picked up 14,000 more votes in Gwinnett County and 12,800 votes in Cobb County. He even found almost 4,000 additional votes in his home county of Hall.
While Handel crushed Deal again in her home county of Fulton, Deal still built his total by 6,000 votes over the primary.
Deal saw his vote totals fall in only five of 159 counties, while Handel's dropped in 15 counties.
Clearly, said University of Georgia political scientist Charles Bullock, an expert on runoff elections, Deal did a better job of picking up the votes of those who originally supported one of the five other Republican candidates in the primary.
House Speaker David Ralston, R-Blue Ridge, whose first year as speaker required him to heal a fractured GOP caucus, said the same must now happen across the state. Speaking at a "unity breakfast" the GOP held in Buckhead on Wednesday, Ralston said he was greeted by a Barnes television ad while he was preparing for the event.
"This is going to be a tough, tough fall," Ralston said. "The other guy is up on TV and he is working hard and is going to be formidable opponent."
Later, Perdue issued a statement that emphasized GOP unity, calling Deal a "common-sense conservative who has consistently represent the principles and beliefs of our state's citizens."
"Now it is time for our family to come together and keep Georgia moving forward," the governor said.
Barnes, meanwhile, did not cede the day to the Republicans. He was e-mailing reporters and using Deal's victory to raise money.
“The runoff was certainly hard-fought and I congratulate Congressman Deal on his victory," Barnes said in a statement. "But it doesn’t matter who my opponent is, this election is about the serious issues facing all Georgians, not the out-of-state endorsements and sideline issues that the other team has used to divide voters."
Deal's victory made national news Wednesday at the daily White House briefing. When a reporter asked press secretary Robert Gibbs about Deal winning the nomination despite having raised questions as to whether President Barack Obama is a U.S. citizen, Gibbs said Deal might have other worries.
"That may soon be the least of his concerns, in terms of some ethics investigations currently ongoing," Gibbs said, apparently in reference to a congressional report from earlier this year that said Deal likely violated House ethics rules. The Atlanta Journal-Constitution first reported the charges and the subsequent news last month that a federal grand jury was asking questions about the situation.
"The White House knows as little about Georgia politics as it does about creating jobs," Deal spokesman Brian Robinson said.
Staff writer Steve Visser contributed to this article.