"Regardless of what happens, it's going to be a 10-person race," Kingston said in a telephone interview from Israel, where he was traveling with other lawmakers. "And I think you'll probably have a self-funder in there, and you can have a mad scramble."
Among other potential Republican candidates is four-term Rep. Tom Price from a district north of Atlanta.
Other possible Republican candidates are two other House members Reps. Paul Broun and Phil Gingrey, both physicians. Broun gained national attention last year when he described evolution as a lie "from the pit of Hell." Gingrey claimed the spotlight earlier this month when he defended controversial statements about abortion made last year by failed Missouri Senate hopeful Todd Akin.
Chambliss was first elected to the House in the 1994 Republican wave. He moved up to the Senate after a bruising 2002 campaign in which he defeated Democratic incumbent Max Cleland, a triple amputee from his Vietnam war service.
He was criticized for a slashing campaign against Cleland that included an ad, featuring terrorist mastermind Osama bin Laden and Iraqi President Saddam Hussein, criticizing the Democrat a decorated Vietnam War veteran for his record on defense and homeland security issues. Even some of Chambliss' fellow Republicans said it went too far.
Guy Cecil, executive director of the Democratic Senatorial Campaign Committee, said Democrats will try to win back the seat.
"Georgia will now offer Democrats one of our best pick-up opportunities of the cycle," Cecil said. "There are already several reports of the potential for a divisive primary that will push Republicans to the extreme right. Regardless, there's no question that the demographics of the state have changed, and Democrats are gaining strength. This will be a top priority."
Democrats hold a 55-45 advantage in the Senate but will be defending more seats next year 20 to the GOP's 13. Democrats will be scrambling to hold onto the seat in GOP-leaning West Virginia, where five-term Democratic Sen. Jay Rockefeller recently announced he would not seek re-election. Republican Rep. Shelley Moore Capito is running for the Senate seat.
Democratic incumbents also face tough re-election races in Arkansas, Louisiana, Montana, North Carolina and Alaska all states that went Republican in the last presidential election.
An open seat in Georgia, which has trended Republican, presents a legitimate opportunity for Democrats, especially if the GOP faces a divisive primary. Potential Democratic candidates are conservative Rep. John Barrow, who has survived redistricting in his House races, and Atlanta Mayor Kasim Reed.