If the New Hampshire primary is all over but the shouting, then it’s time for South Carolina to brace for the whispers.

With just 10 days to go before the Jan. 21 primary and some conservatives openly desperate to halt the momentum of former Massachusetts governor Mitt Romney, voters and political operatives alike are girding for the kind of whisper campaigns, viral innuendo and dubious personal attacks that have made South Carolina a state where the politics are as harsh as the tea is sweet. Already, a blitz of negative ads are expected to hit the airwaves, funded by outside groups that have no intention of using their inside voices.

“They fight pretty rough here, that’s for sure,” said Charles Green, a retired teacher eating country-fried steak at Lizard’s Thicket in downtown Columbia, a meat-and-three popular with visiting candidates. “It’s usually a pretty good show waiting to see to what they’ll come up with next.”

Candidates here have been ambushed with accusations ranging from distorted to invented. It was during the Republican presidential primary race here in 2000 that recorded calls asked voters whether they were aware that Sen. John McCain had fathered an illegitimate black child, a merciless twist on the fact that McCain and his wife Cindy have an adopted daughter from Bangladesh.

In 2008, a state Senate campaign allegedly paid an undocumented immigrant to infiltrate a crew painting the house of an opposing candidate, and then accused him of hiring illegal workers.

Two years later, then-candidate Nikki Haley was hit with two charges of adultery in the days before her run-off race for the Republican gubernatorial nomination. Several of her critics, including a party official supporting her opponent and an evangelical radio host, also raised questions about her sincerity as a Christian. (Haley, who was born in South Carolina of Sikh immigrant parents, became a Methodist after marrying in 1996.) The attacks were not enough to keep Haley, a favorite of tea party conservatives, from winning the nomination, and then the governorship.

“We have a rough-cut side to politics that really doesn’t fit with the gentle nature of the people who live here,” said former governor Mark Sanford (R), who managed to serve out his final term despite being caught in a spectacularly public affair with a woman in Buenos Aires that had state lawmakers demanding his resignation.

So far this year, the smear front has been quiet. But observers say the nastiest charges aren’t likely until closer to Election Day. And given South Carolina’s consistent role in anointing the eventual winner of Republican nomination battles, they don’t expect this to be the year campaign consultants decide to slip on the white gloves.

“South Carolina is a competitive state and it’s always been in important in the process,” said Katon Dawson, a former chairman of the South Carolina Republican Party who is advising Texas Gov. Rick Perry. “There are a lot of campaign operatives and some of them are going to make mischief.”

To be sure, some of the crudest of the guerrilla tactics have been stripped from the consultant arsenal. Campaign finance and disclosure laws, along with restrictions on push polling and robocalls, make it much harder to deliver an anonymous smear over the phone lines. Today’s attacks are less likely to be in whispers than viral e-mails, YouTube videos and slashing TV and radio ads.

“They can do the negative stuff, but it’s more difficult to do the unattributed in-the-gutter hit than it used to be,” said Richard Harpootlian, the state’s Democratic Party chairman.

And new to this year’s campaign: super PACs able to spend unlimited ad money on a candidate’s behalf. They are likely to blow a hot wind of negative airtime across the state, as they did in Iowa when a group supporting Romney unleashed a withering assault on former speaker of the House Newt Gingrich. And that was Iowa.

This time Romney, who heads to South Carolina leading in the polls, will be on the receiving end of millions of dollars worth of attack ads on everything from his record on abortion rights to his alleged corporate greed when he ran Bain Capital.

“It’s going to be a free-for-all here, is my take,” said Sanford, a veteran of numerous local and statewide races. “South Carolina has had a tragic history of Wild West campaign antics, and I don’t think that’s over.”

One topic of whispered censure could be the front-runner’s faith. Some of his opponents — or their surrogates — might look for ways to quietly emphasize Romney’s Mormonism to the state’s many evangelicals.

Frank Chesno, a Romney supporter eating breakfast near the state capitol building, has already heard the questions.

“It seems like a grass-roots thing, some people saying, ‘I can’t vote for Romney because I don’t think Mormonism is Christianity,’ ” said Chesno, 68, a hospital administrator. “It’s definitely out there.”

Tony Beam, the Christian broadcaster in Greenville who questioned Haley’s religious identity in 2010, said he didn’t expect Romney’s religion to be a major factor among evangelicals for the simple fact that they don’t like him anyway.

“I think that if the Mormon issue was off the table, he still would not get a lot of support from evangelicals,” said Beam, who has endorsed Perry. “For most people, the focus is on his political history of being back and forth on the major social issues” such as abortion and same-sex marriage.

But several other politically savvy South Carolinians said they fully expected a robust, if discreet, critique of Romney’s faith as others try to shove the fast-rolling Mitt-night Express off the rails.

“They have to gin up their own turnout,” said Harpootlian. “The way they do that is to scare people: ‘If you don’t turn out to support Santorum or Perry, we’re going to end up with a nominee who believes the Garden of Eden is in St. Louis.’ ”

If Iowa’s special ring of candidate hell is being expected to eat a waffle-coated hot dog, and New Hampshire’s is the risk of being bitten by a goat, South Carolina’s torture is knowing your whole campaign might suddenly veer into questions of your fidelity, faith or mental health.

And the nasty tactics aren’t just distracting; they often work.

McCain was the solid front-runner when the whispers about his “illegitimate” child took off in 2000. His support plummeted, and George W. Bush went on to win South Carolina and eventually the nomination.

During a 1978 congressional race, Max Heller, the popular Democratic mayor of Greenville, seemed to be headed for victory over Republican Carroll Campbell. But that lead evaporated after push polls emphasized to voters in the heavily evangelical district that Heller was Jewish.

A no-chance third candidate also joined the race and gave anti-Semitic speeches in local churches. It has long been rumored that the third candidate was orchestrated by Campbell’s young campaign manager, Lee Atwater, who would go on to gain a national reputation as a political kneecapper.

“I myself answered phone calls that Max would send troops to Israel immediately if he won,” recalled Heller’s widow Trude Heller, 89, who settled with her husband in South Carolina after the two fled from Nazi Austria. “It was crazy, but it worked. He was ahead 13 points and then he lost big. ”

That’s been the way of things for a long time in South Carolina, a tradition-minded state about to put its political civility to the test once again.