The sprint to Georgia’s December Senate runoff is on, and both Sen. Saxby Chambliss (R) and his Democratic challenger, Jim Martin, are working feverishly to refill campaign coffers that were drained in the lead up to the close Nov. 4 election.

Fundraising letters have gone out, well-known party leaders are coming in and independent expenditures are already being spent on TV ads in media markets around the state.

On Wednesday morning, Chambliss estimated his campaign, which essentially started from scratch after Nov. 4, had raised more than $1 million in the past week.

That number should only increase with Sen. John McCain (R-Ariz.) scheduled to drop into the state on Thursday and former Arkansas Gov. Mike Huckabee (R) slated to campaign with Chambliss on Sunday.

In addition, Chambliss said he’s reached out to Alaska Gov. Sarah Palin (R) and former Republican presidential hopefuls Rudy Giuliani and Mitt Romney to come into the state before the Dec. 2 runoff.

“Those are the kind of folks who do get our base energized,” Chambliss said of his campaign’s prospective surrogate lineup.

Asked how a runoff transpired in a contest that many political observers once thought would be a slam-dunk for the Senator (even with a Libertarian candidate in the race), Chambliss laid most of the blame on the economic crisis and voter anger over his vote in favor of controversial bailout legislation earlier this fall. Chambliss just barely missed getting over the 50 percent mark in the Nov. 4 balloting, which would have avoided the runoff.

“After certain conditions were met, I voted for the rescue package, and that got a lot of conservatives upset,” Chambliss said.

But since the election, Chambliss pointed to anecdotal evidence that some voters’ minds have changed.

“I’ve had dozens and dozens of people who called up … and said: ‘We were upset with you because of your vote on the rescue package. We voted early, and we shouldn’t have done that because on Election Day we had a better understanding of why you did what you did,’” he said.

Chambliss said those voters are now energized and are now on board with his campaign, especially with Republicans making 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.

While it seems unlikely that Democrats would reach 60 seats in the Senate even if they do win in Georgia — two other Senate races have not been called but are leaning toward Republicans — Chambliss said Wednesday that the mere possibility of a filibuster-proof majority is going to be a major motivator for Republicans to come out to the polls in December.

“People are understanding what a filibuster-proof majority in the Senate would do,” Chambliss said.

Meanwhile, Martin is out with a new fundraising letter Wednesday in which he asks supporters to help him raise a quarter-million dollars in the next 10 days. In that letter, Martin discusses the implications of what a Democratic victory in Georgia’s Senate contest will mean for the new Obama administration.

“President-elect Obama is going to need all the help he can get in Washington,” Martin wrote. “Real change doesn’t come easy — you’ve got to have help. I need your help to win this runoff, and Barack Obama’s going to need help from people like me to shake up Washington.”

Obama’s campaign has reportedly sent staffers to work for Martin’s runoff campaign, but it’s unclear yet whether the president-elect will get personally involved in the race in the next three weeks.

Well-know Democratic strategist Donna Brazile, a Roll Call contributing writer, also released a fundraising letter today discussing the importance of the race and asking supporters to donate to the Democratic Senatorial Campaign Committee.

The DSCC has already released a Web ad ahead of McCain’s visit that seeks to remind Georgians that the Arizona Senator once denounced a controversial Chambliss ad during his 2002 campaign against former Sen. Max Cleland (D).

The DSCC cites a statement by McCain calling the ad “worse than disgraceful.”

But the National Republican Senatorial Committee is also going all out in the runoff. Several Web ads have already been released by the NRSC, and a new TV ad is up Wednesday attacking Martin for voting for a series of tax increases during his time in the state legislature. Meanwhile, one of the NRSC’s Web ads is titled “It All Comes Down to Georgia” and paints the runoff race as the last line of defense against a filibuster-proof majority and giving Obama “a rubber stamp Senate.”

But even with those ads, Martin spokesman Matt Canter said Democrats are the ones with momentum in Georgia right now.

“Republican donors in Georgia and across the country are feeling in large part frustrated by the leadership and by the campaigns that Republicans ran and lost culminating in last week’s election,” Canter said. “People are incredibly enthused here in Georgia and excited across the country for Jim Martin’s campaign.”