Georgia Sen. Saxby Chambliss, R, will not seek re-election in 2014, a Republican official told NBC News on Friday.
The two-term senator is the top Republican on the Senate Intelligence Committee and has joined in some bipartisan efforts on fiscal issues, making him a prospective target for conservative primary challengers next year.
A number of Republican lawmakers in the state might now seek the Senate seat, and Democrats are vowing to play offense in the typically GOP-leaning state, too.
"Georgia will now offer Democrats one of our best pick-up opportunities of the cycle," said Guy Cecil, the executive director of the Democratic Senatorial Campaign Committee.
NBC's Michael O'Brien contributed.