The December runoff between Sen. Saxby Chambliss (R-Ga.) and former state Rep. Jim Martin (D) has become one of the final battlegrounds of the 2008 cycle and could well be the key to Democrats’ winning a filibuster-proof majority in the Senate come January.

And yet, two weeks removed from the Nov. 4 elections — with national figures descending on the state and both parties airdropping massive amounts of cash there — many Republicans are still looking back and scratching their heads about how Martin made a competitive race out of a contest that many once thought would be a slam-dunk.

Those Republicans tend to agree that it wasn’t the strength of Martin’s campaign that put Chambliss in such a precarious position. A series of policy positions taken by the first-term Senator left him struggling with his party’s base, and then the financial meltdown and the controversial bailout bill created a perfect storm of bad press that put the Senator in a particularly vulnerable position at a crucial moment. Then national Democrats exploited the opening with a massive spending blitz.

But some state Republicans are also casting blame on what they describe as a poorly run campaign that had to be resuscitated in the final weeks before the November election by a National Republican Senatorial Committee that already had plenty of other contests to worry about.

One Georgia Republican insider last week pointed the finger at Chambliss’ longtime political strategist Tom Perdue for putting together a weak direct-mail program and “substandard” and “impersonal” television commercials during the crucial late summer and fall months.

Known in Georgia for his hard-nosed tactics, Perdue has been credited for engineering Chambliss’ defeat of then-Sen. Max Cleland (D-Ga.) in 2002 in a race remembered largely for its nasty ads.

Perdue’s other monumental victories were also in races where his candidate was challenging an incumbent. He masterminded the late Sen. Paul Coverdell’s (R-Ga.) upset victory over then-Sen. Wyche Fowler (D) in 1992 and was instrumental in former Senate Majority Leader Bill Frist’s (R-Tenn.) defeat of then-Sen. Jim Sasser (D) in 1994.

“There are a lot of people that are not real happy with the campaign Tom Perdue ran in the general election,” the source said last week. Sources indicated that that sentiment reached a boiling point about three weeks before the general election, just after the bailout vote.

Chambliss had already earned some enmity among his conservative base in Georgia by supporting a compromise immigration package last year. Then in early August he emerged as a founder of the “Gang of 10” Senators who were pushing a bipartisan energy compromise that advocated both oil drilling and alternative fuels. Neither position helped him with his base, but Chambliss’ support of the financial bailout appeared to be the straw that broke the camel’s back. While fellow Georgia Sen. Johnny Isakson (R) also supported the bailout, none of the state’s Republican House Members — who, unlike Isakson, were up for election in November — voted for the bill.

It appears the NRSC began to get more heavily involved in Chambliss’ race not long after the Senator released a TV commercial in which he told voters why he supported the bailout package. It’s a move that appeared to confirm the old political adage that if you’re explaining, you’re losing. At that point, the campaign’s direct-mail program, which didn’t begin until mid-September, was less than a month old.

“It became clear that Saxby was going to need a lot of help and that the campaign was not heading in a positive direction. … [The campaign] was on autopilot, and it needed some jumper cables,” the Georgia source said.

Chambliss spokeswoman Michelle Grasso took issue with that assertion, arguing that regardless of prognosticators’ early determination that Chambliss appeared to be a shoo-in for re-election, “we always had a very aggressive campaign. … That was the way Sen. Chambliss runs a campaign and Tom Perdue runs a campaign — we don’t take anything for granted.”

As for questions about the campaign’s television strategy, she dismissed those who play Monday morning quarterback.

“When you’re running positive ads you have a lot of people say you should be running negative ads and when you’re running negative ads people say, ‘Why are you running negative ads? You should be running positive ads.’”

What is clear is that as the NRSC restructured its spending plans in mid-October amid the fallout from the financial crisis and an increase in national Democratic spending in places like Georgia. Resources were shifted from Senate races like Colorado, where GOP prospects appeared to dim, to newly emerging races like the once-safe Peach State seat.

By the last week of the election, the Georgia contest had become the second-highest priority for the NRSC in terms of independent expenditures. The committee spent more than $1.3 million on the Georgia contest in the final week of the campaign, a total that was behind only Minnesota, where the committee spent nearly $1.8 million. (In comparison, the Democratic Senatorial Campaign Committee spent nearly $1.6 million in Georgia in the final week before Nov. 4.)

In the end, Chambliss was unable to secure the more than 50 percent of votes necessary to win the campaign outright and avoid the runoff. He took 49.8 percent to Martin’s 46.8 percent, with a Libertarian candidate taking 3.4 percent in the race.

As he’s begun a new media blitz for the runoff, Chambliss continues to answer questions about what happened in the general election. Last week, he defended the way his campaign was run and laid the blame for the runoff squarely on the economic crisis and voter anger over his support of the controversial bailout bill.

“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. He said he has heard from dozens of people who said they voted early but now regret their choice.

In an interview, Isakson agreed that the state’s large number of early voters likely had a major impact on how close the campaign was, especially with all the turmoil that surrounded the country’s financial situation throughout the month of October.

“I’ve been in this business 34 years. You always designed your game plan to peak on Election Day,” Isakson said. “Now you really need to peak twice, once on the first day of early voting and then come back and peak again on Election Day. It really moves back your advertising requirements.”

Republicans are hoping to energize GOP voters for the runoff by making the case that the Georgia contest might be all that is standing in the way of Democrats winning a 60-seat majority in the Senate.

The NRSC is helping in that effort with several staff on the ground and $700,000 worth of TV ad buys in just the first week of the runoff.

But the DSCC is also continuing to go all out for Martin and dropped $750,000 into the state through last Thursday.