How far can Herman Cain go?

Does Herman Cain actually have a chance to win the Republican nomination?

There's no question that Cain, who was essentially unknown when he entered the presidential race, remains a serious long shot. But it's starting to look slightly more plausible that the former Godfather's Pizza CEO could actually become the Republican presidential nominee.

Cain earned a round of positive media coverage for his strong upset victory in the Florida straw poll last weekend, and he's getting traction with his 9-9-9 tax plan - a proposal to replace the current tax code with a nine percent flat income tax, a nine percent corporate tax and a nine percent national sales tax. When a moderator asked Cain about the plan at last week's Republican debate, the audience broke into applause even before he finished asking the question.

Now a Fox News poll shows Cain with 17 percent support- putting him just two points behind Rick Perry and six points behind Mitt Romney. It's just one poll, of course. But if it's accurate, it represents a near tripling in support for Cain from the previous Fox poll. And even if the poll is an outlier, it helps Cain with fundraising and means another round of glowing media coverage. (An endorsement from Fox News commentator Dennis Miller, meanwhile, can't hurt. ) 

Cain burst out of the gate with his performance in the first Republican presidential debate, which was strong enough that a Fox News focus group deemed Cain the clear winner. But he soon ran into trouble over controversial comments (perhaps most prominently, his statement that he wouldn't tap a Muslim to serve in his cabinet) and an unwillingness to offer specifics on foreign policy.

Cain spent the summer in the back of the GOP pack, polling well enough to earn a spot on debate stages but badly enough that the media treated him as a second- or third-tier candidate. His rivals, meanwhile, clearly did not see Cain as a threat and thus declined to take shots at him.

That will change if more polls show a surge in support for Cain. And that's not inconceivable: Gallup has found Cain has the highest positive intensity score of all the GOP candidates among those who know who he is. (Positive intensity is a measure of strongly favorable opinion vs. strongly unfavorable opinion.) Cain is known only by about half of Republicans and Republican-leaning independents; if his positive intensity score holds up as he becomes more well known, he could give Romney and Perry a run for their money.

But money, as it were, is a problem: While Romney and Perry have a ton of it, Cain lacks the fundraising network of his better-known rivals. And that's not the only issue. Cain is competing with Perry, Michele Bachmann and Rick Santorum for social conservatives, and that means he needs to do respectably in Iowa, where they make up a major chunk of the GOP electorate. But Cain has little organization in the state - as evidenced by his fifth place finish in the Iowa straw poll - and some his staff in the state quit because they didn't think the campaign was putting in a serious effort.

A Cain campaign official acknowledged to CBS News that the candidate is unlikely to win Iowa. But the campaign hopes to survive the state - a third-place finish would be enough, though Cain has claimed he'd be "ecstatic" with fifth-place - and then hold on until South Carolina.

It's a state Cain's campaign believes the candidate can win -- and thus eventually get to the White House. Cain hails from nearby Georgia, where he hosted a radio show that could be heard across the border; the state is also 28 percent African-American and highly religious, which makes it demographically appealing for Cain, a Baptist minister. And the open primary means Democrats and independents who support Cain can cast ballots.

Still, there's a lot of distance between where Cain stands today and a victory in South Carolina, where he currently polls in the single digits. And Cain will likely not have the resources to match Perry or Romney's get-out-the-vote effort in the state. But there's no denying that Cain's candidacy suddenly seems a bit more viable - and no doubt that his rivals are starting to pay attention.