COLUMBIA, S.C. • Now is the time that GOP presidential candidates, vying to be the "Romney alternative" in South Carolina, could take their cues from South Carolina's history book: Play dirty.

GOP front-runner Mitt Romney said he was ready to defend himself from the "underbelly" of politics in a state known for bare-knuckled tactics.

"Politics ain't bean bags, and I know it's going to get tough," the former Massachusetts governor said. "But I know that is sometimes part of the underbelly of politics."

In South Carolina — with its tradition of whisper campaigns, automated phone calls for which no one takes credit and potentially illegal efforts to sway voters — politics is a blood sport, supported by a cottage industry of political strategists.

Anticipation is building as to whether the next week and a half, leading up to the state's first-in-the-South primary, will result in the rough tactics for which the state is notorious.

Traditionally, South Carolina is where the gloves come off. Candidates have slugged it out in the two early-voting states — Iowa and New Hampshire — and some are seething mad at the others.

There is cash to support campaign efforts — clean or dirty — allowing candidates who must make up ground to attack. For example, the super-political action committee supporting former U.S. House Speaker Newt Gingrich, angry at Romney over Gingrich-bashing ads in Iowa, is enjoying a $5 million boost from a casino mogul. Meanwhile, Texas Gov. Rick Perry's campaign remains flush even as Perry, who has fared poorly thus far, faces the prospect of winning or going home after the Jan. 21 South Carolina primary.

Much is on the line. Since 1980, the winner of the South Carolina GOP primary has gone on to win the Republican nomination every time. The candidate who wins the Palmetto State will get a mighty bounce that far exceeds those from Iowa and New Hampshire.

"History always repeats itself, and this state has the reputation of playing hard," said Larry Marchant, a political consultant who is not working for any of the presidential candidates. "I expect it to get bare knuckles here."

Marchant knows. He perhaps is best known for his 2010 statement that he had sex with then-gubernatorial candidate Nikki Haley. Marchant offered no proof, and Haley, a married mother of two, denied the claim and won the election.

Others doubt the primary will get nasty.

"We are in a new era of communications that doesn't allow you to get away with the dirty tricks of the past," said Wes Donehue, a South Carolina political consultant who was working for U.S. Rep. Michele Bachmann of Minnesota, until she bowed out of the race after a poor showing in Iowa. "You can't go anywhere without someone being there with a video camera."

Donehue knows a thing or two about tricks. During the 2008 GOP primary, reporters used Internet resources to discover that Donehue was behind the PhonyFred.org website, which anonymously attacked Republican candidate Fred Thompson.

But Donehue says he has seen tricks far more sordid, including a bogus Christmas card sent to the state's GOP activists during the 2008 race. The card, claiming to be from the Romney family, included controversial quotes from the Book of Mormon.

Today, however, Donehue says super PACs have become the new way to play rough. A recent U.S. Supreme Court ruling allows unlimited contributions to and spending by the committees so long as they do not coordinate efforts with the actual campaigns.

"The negative attacks won't be anonymous whisper campaigns," Donehue said. "They'll be on TV for the world to see."

So far, the most negative South Carolina ad is one from a super PAC that supports Gingrich. It portrays Romney as an unsavory capitalist during his tenure at private-equity firm Bain Capital. The ad includes interviews with people who lost their jobs at companies bought by Bain including one in Gaffney, S.C.

There are likely to be plenty more negative ads, predicts Richard Quinn, a longtime South Carolina Republican consultant now working for former Utah Gov. Jon Huntsman.

Quinn points to the anti-Gingrich ads run by the super PAC supporting Romney before the Iowa caucuses as proof that negative ads work. "Gingrich was ahead in Iowa according to the polling. But not after those ads. Those attack ads were probably just as relentless and the same level of intensity as the one run against us in 2000."

Quinn is referring to perhaps South Carolina's most notorious example of dirty politics. In 2000, a whisper campaign led many of the state's voters to wrongly think GOP presidential contender John McCain, for whom Quinn worked, had fathered an African-American child and his wife was a drug addict.

McCain got the last laugh eight years later, winning the 2008 South Carolina GOP primary and going on to capture the Republican nomination.