Updated Dec. 2, 1:12 p.m.

Coming off a visit Monday in which Alaska Gov. Sarah Palin (R) sought to fire up the party base for Sen. Saxby Chambliss (R), Peach State Republicans say they are cautiously optimistic about their prospects of holding the state’s “firewall” Senate seat in today’s runoff.

Chambliss, who fell just short of earning a second term in a three-way contest on Nov. 4, is facing Democrat Jim Martin in a runoff because Georgia election law requires a candidate to earn more than 50 percent of the vote to claim victory.

Along with campaign ads that saturated Georgia television over the four-week runoff sprint, get-out-the-vote efforts became a key component of both campaigns in recent days. Reports on Tuesday morning indicated a very low turnout for the runoff, but both sides are continuing to press their supporters to get to the polls.

“Early reports indicate that turnout is extremely light today, making every vote that much more important,” Martin said in an e-mail to supporters Tuesday. “Please remember to vote, and tell your friends and family to vote.”

Late polling numbers give Chambliss the edge in the contest. A Public Policy Polling survey taken over the weekend showed the Senator up by 7 points. But Democrats preferred to point to a Democratic Senatorial Campaign Committee poll released last week that showed Martin behind but still within the margin of error.

If Martin were to knock off Chambliss today, his victory would be the biggest upset of the Senate cycle. When Martin emerged from a runoff to win the Democratic nomination in Georgia, he was viewed as little more than a sacrificial lamb in what had been considered a safely GOP seat. But that was before Chambliss’ campaign was hit hard by the country’s economic downturn and before national Democrats made the race a priority in their late election spending.

“We feel great about Sen. Chambliss’ chances to win the runoff,” National Republican Senatorial Committee spokeswoman Rebecca Fisher said. Chambliss “has the momentum on his side and Republicans have made a very strong effort on the ground over the past three weeks.”

That effort has come first and foremost in the form of campaign cash. After a $900,000 ad buy Wednesday, the NRSC had spent $2.6 million on the runoff race. Meanwhile, the DSCC had spent about $1.5 million as of last week.

Over the past three weeks, the runoff has not been a fight over the middle ground but rather a race for each party’s base voters.

That battle can certainly be seen in the third-party independent expenditures in the race. In the past week alone, Chambliss has earned support from the National Right to Life Political Action Committee and the National Rifle Association, while Martin has been promoted by NARAL Pro-Choice America and the League of Conservation Voters.

But both campaigns are also clearly targeting their bases for what is expected to be a low-turnout affair. Republicans have made the case that the Georgia contest might be all that is standing in the way of Democrats winning a filibuster-proof majority in the Senate.

“Chambliss has certainly portrayed himself as the last line of defense between responsible government and wild-eyed radicalism,” said Charles Bullock, a University of Georgia political science professor.

“For years here in Georgia, a theme of Republican campaigns has been that the Democratic opponent is too liberal for the jurisdiction,” Bullock said. But during the runoff, Republicans have ramped up that rhetoric.

“Rather than saying that Jim Martin is too liberal, he is now too radical for Georgia,” Bullock said.

But Democrats have not shied away from injecting into the race some party leaders who traditionally haven’t played well in the conservative Peach State.

The most recent example is Massachusetts Sen. John Kerry (D), who released a fundraising letter Monday for Martin urging Democrats to “remain vigilant, because Republicans could still control enough seats to obstruct everything we need to do. … We must help Jim Martin win the Georgia runoff and reject Saxby Chambliss and his brand of ‘Swift Boat’ politics.”

Other potentially polarizing party leaders who have stumped for Martin are former President Bill Clinton and former Vice President Al Gore.

Along with Palin, Chambliss has hosted Sen. John McCain (R-Ariz.), former Arkansas Gov. Mike Huckabee (R) and former Massachusetts Gov. Mitt Romney (R) in the state.

But as the runoff draws to a close, it appears that the country’s biggest political celebrity, President-elect Barack Obama, will take a pass on visiting Georgia before the runoff.

While Obama has cut radio ads and robocalls for Martin, the campaign had held out hope that the president-elect would headline an event in the state for Martin. Obama’s appearance in the state was seen as potential key to bringing out black voters again in the special election after a strong showing on Nov. 4. Figures from the Georgia secretary of state show black participation among early voters down more than 10 percent from what it was during the lead-up to the general election.