"We just kicked off our campaign to take the seat back from John Barrow ...," he said. "We are fired up."
With 95 percent of the precincts counted, Mr. Barrow, now a Savannah Democrat, had 161,374 votes compared to 80,784 for his Republican challenger.
"I would attribute it to my efforts to stem the partisan bickering that's going on in Washington," Mr. Barrow told The Savannah Morning News. "I've tried to make it my policy to work on both sides of the aisle ... to find solutions to problems that are plaguing people back home.
"I know that's what people tell me they want. And I genuinely believe that's what we need in Washington. ... I'm very optimistic that we'll see more of that."
Tuesday night's outcome was a huge contrast with the 2006 election, when Mr. Barrow beat former Republican congressman Max Burns by only 864 votes.
But Mr. Stone was unbowed, vowing to return.
A boundary shift had removed Mr. Barrow's hometown of Athens from the 12th. But, settled in Savannah since 2006, Mr. Barrow seemed more comfortable with the district.
Mr. Barrow touted his independence - he bucked his party more often than any House member last year - and the federal money he has won for the district.
Mr. Stone, a former aide to Mr. Burns, as well as the late U.S. Rep. Charlie Norwood, tried to convince voters that Mr. Barrow had done too little about illegal immigration, dependence on foreign oil and unfair taxes.
He also chided the incumbent for voting against the U.S. troop surge in Iraq as a vote against the troops.
But Mr. Barrow outflanked Mr. Stone by winning the support of conservative-leaning groups such as the Veterans of the Foreign Wars and the National Rifle Association.
He also was endorsed by groups representing big and small businesses, as well as by supporters of immigration restrictions.
Enthusiasm for Democratic presidential candidate Barack Obama also likely boosted turnout among blacks. They reliably support Democrats and represent about 40 percent of the district's voters.
Unlike 2004 and 2006, when Mr. Barrow ran against a well-funded foe - Mr. Burns - Mr. Barrow had a big financial advantage this year. As of Sept. 30, he still had $546,000 stashed away, even after having spent $918,000 during the previous three months.
In contrast, Mr. Stone had less than $33,000 left after spending about $108,000 in the quarter.
Unlike 2002, 2004 and 2006, the national GOP did not make the 12th District a high priority and provided Stone almost no help.
"We feel like we beat John Barrow, but we got beat by the Democratic Congressional Campaign Committee and the National Republican Congressional Committee," Mr. Stone said.
He said the latter actively steered conservative campaign contributors away from the 12th District so their money could be used in other contests.
"We have to clean house there and get new leadership at the NRCC," Mr. Stone said.