Republicans will have to defend at least one Senate seat without its incumbent in 2014.  Saxby Chambliss informed his staff that he will not seek re-election in 2014, leaving an open seat in deep-red Georgia to fill:

Republican Sen. Saxby Chambliss will announce Friday that he will retire from the U.S. Senate and not seek a third term next year.

The Atlanta Journal-Constitution reports Chambliss informed his staff this morning.

Chambliss was a member of the so-called “Gang of Six,” a bipartisan group of senators that tried last year to forge an agreement on ways to reduce the debt. Rep. Paul Broun, R-Ga., had been considering a challenge to Chambliss in a GOP primary.

Chambliss, 69, was first elected to the Senate in 2002 after serving in the U.S. House for four terms. He defeated Democratic incumbent Max Cleland, a Vietnam veteran and triple amputee, in that first race after running controversial ads that included images of Saddam Hussein and Osama bin Laden.

In 2008, Chambliss had a closer-than-expected fight against Democrat Jim Martin, winning by only 3 percentage points.Democrats were buoyed by high-turnout in the presidential primary that year, and poured resources into defeating Chambliss.

Chambliss hasn’t exactly been a darling of the Right, although his voting record is still conservative:

Chambliss has grown increasingly frustrated with the pervasive gridlock in the Senate — particularly its inability to reach a grand bargain to slash deficits.

The move is certain to prompt furious effort among Republicans to hold onto the seat. After working with a bipartisan group of lawmakers, first known as the Gang of Six, Chambliss came under criticism from the right for advocating a major deal with higher tax revenues. Still, he appeared in a strong position to fend off a primary challenge from the right.

This will produce an opening for Tea Party activists and a challenge for the GOP establishment.  John Cornyn warned earlier that the NRSC would start getting more involved in candidate recruitment after grassroots candidates in Missouri and Indiana lost races that had widely been predicted as relatively easy wins for Republicans.  This may be the first test of this establishment activism, as the GOP can hardly afford to lose a Senate seat from the South.

The AJC’s Jim Galloway notes that a few names are already getting some play:

More members of Congress – including Phil Gingrey of Roswell and Tom Graves of Ranger – are certain to consider the race now that it lacks an incumbent. In the state Capitol, one name has already popped up — that of state Sen. Ross Tolleson, a Republican who hails from former U.S. senator Sam Nunn’s home town of Perry.

On the Democratic side, U.S. Rep. John Barrow of Augusta has said he wasn’t interested in challenging Chambliss. Whether or not that disinterest applies to an open seat may be another matter.

Who else might be interested in the opening?  Both Herman Cain and Newt Gingrich have national followings, and both have substantial credibility on the Right.  Cain has been very popular with the Tea Party. I’d guess that at least one of them will start exploring a new campaign in the near future.

If Cain is interested in jumping into the race, at least he can provide continuity for Chambliss’ latest effort:

Wednesday night, U.S. Senator Saxby Chambliss (R-GA), introduced S.122, The FairTax Act, which would implement a simpler, less-cumbersome tax code. Chambliss has introduced the FairTax legislation every year he has been in the Senate.

“The current tax code has become too burdensome and complex, and is filled with provisions that only benefit a few Americans at the expense of everyone else. That’s simply not right,” said Chambliss. “The FairTax Act would create a fairer, simpler tax code that allows every American the freedom to determine his or her own priorities and opportunities.”

The Fair Tax was an integral part of Cain’s presidential agenda.