This post was updated at 12:12 p.m. ET
Two-term Sen. Saxby Chambliss, R-Ga., announced today that he will not run for reelection in 2014.
"After much contemplation and reflection, I have decided not to run for re-election to the Senate in 2014," said Chambliss in a statement. "I am humbled by and grateful for the extraordinary trust of Georgians, who have allowed me to represent them for 20 years in the United States House and Senate."
His decision will likely create what could be a hard-fought primary among Georgia Republicans itching to replace Chambliss. Several Republican House members from Georgia, including Reps. Paul Broun and Tom Price, had been mulling primary challenges to Chambliss, who drew fire from his right flank over his willingness to broker a bipartisan deficit reduction deal that included new revenues.
Those differences fell into stark relief this month, when Chambliss voted in favor of the "fiscal cliff" agreement negotiated in the Senate, but every single GOP House member from Georgia voted against it.
Chambliss downplayed the suggestion that the possibility of a primary fight factored into his decision, saying, "Lest anyone think this decision is about a primary challenge, I have no doubt that had I decided to be a candidate, I would have won re-election. In these difficult political times, I am fortunate to have actually broadened my support around the state and the nation due to the stances I have taken."
Another high-profile Georgia Republican viewed as a possible contender, former 2012 presidential candidate Herman Cain, ruled out a run, saying in a statement, "My attention is laser focused on exposing the economic pain and suffering to come from a second Obama term, part of which is via my new nationally syndicated talk radio show that is finishing its first week on the air. No I'm not running!"
Chambliss, Georgia's senior senator, served four terms in the House before being elected to the Senate in 2002, when he defeated Max Cleland, a triple amputee and Vietnam veteran who was elected to the seat in 1996.