Republican presidential candidate Donald Trump speaks during a rally at the T. Ed Garrison Arena in Clemson, S.C. (Photo by Kevin D. Liles/For the Washington Post) (Kevin D. Liles/For the Washington Post)

He’s a villainous, predatory developer who seized an elderly woman’s property. He’s a corrupt power broker who sought to buy politicians. And he’s a larger-than-life ice sculpture that melts away under the spotlight.

The Donald Trump attack ads have arrived.

The real-estate mogul faces a sustained, multi-front assault in South Carolina ahead of the Feb. 20 GOP primary, where his detractors are painting a dark portrait of the candidate and challenging his populist authenticity. His opponents and their allied super PACs are pouring millions of dollars into ads running statewide to weaken the billionaire ahead of election day.

With a commanding primary win in New Hampshire proving that he can transform his enormous crowds into actual voters, Trump’s rivals now sense a closing window to stop his momentum ahead of “Super Tuesday” in March, when nearly a dozen states will vote.

The strikingly negative tone of the ads shows the extent to which the target on Trump’s back has grown since his victory last week. For the moment, Trump’s campaign is not fighting back with attack ads of its own in South Carolina, but the candidate is using two powerful tools to defend himself: speeches at rallies that attract thousands and a Twitter account with more than six million followers.

Republican presidential candidate Donald Trump said he likes his odds against Democrats, saying he would love to run against Clinton and called Sanders a "Communist" (Reuters)

Right to Rise, the pro-Jeb Bush super PAC, released a blistering ad Friday criticizing Trump’s business record and his positions on social issues, part of its $12 million ad campaign in South Carolina. “Donald Trump: Look past the boasting and you’ll see right through him,” a narrator says as an ice sculpture replica of Trump melts on screen and ultimately breaks apart.

[How Donald Trump learned to win in New Hampshire]

The Club for Growth, a conservative group that has been in an ongoing feud with Trump, also announced Friday that it would spend $1.5 million attacking the candidate in the state.

“Donald Trump is not a conservative,” said David McIntosh, president of Club for Growth Action. “He is a liberal on taxes, health care, eminent domain, and government bailouts.”

Another group, Our Principles PAC, has already spent at least $2 million attacking Trump in the country’s first two GOP nominating contests, with the bulk of those resources spent on advertising in Iowa. The PAC, headed by former Romney deputy campaign manager Katie Packer, says it will match those efforts in South Carolina. “How much do we really know about Donald Trump?” asks one ad.

“Virtually every core position that Republicans take, he is at odds with,” Packer said Friday. “What we found in Iowa is that when we exposed voters to that information it changed minds.”

During a rally in Baton Rouge on Thursday night, Trump addressed the attacks from Bush and others that he is not a “true conservative.’’

Republican presidential candidate Ted Cruz, shown here in New Hampshire, is attacking Donald Trump ahead of the South Carolina primary on Feb. 20. (Cassi Alexandra/For The Washington Post)

“You know what? In a way I don’t even care about labels,” Trump told a rally crowd of more than 10,000. “I’m a guy with common sense that’s going to make us a fortune.’’

Texas Sen. Ted Cruz’s campaign also released an ad Thursday painting Trump as a corrupt donor seeking to buy influence.

“Trump bankrolled politicians to steamroll the little guy, a pattern of sleaze stretching back decades. Worse? Trump still supporters eminent domain today,” a narrator says.

Trump called the ad “so false” during the Thursday rally and told his supporters that attack ads are “paid for by the special interests, the lobbyists and the donors” and should not be believed.

“It’s difficult because I’m a legitimate person,” Trump said at the rally. “They’re vicious, and they say anything. They say anything.”

[Republicans now see a Trump-Cruz race, with time running out]

The onslaught of negative ads marks an end to the kids-gloves approach that most of Trump’s opponents have taken toward him. He has benefited from the fierce competition between candidates like Bush and Sen. Marco Rubio (Fla.), who have long focused on attacking each other in hopes of capturing establishment-friendly voters.

But Trump has now emerged as a clearer rival in South Carolina, where both Bush and Rubio need a strong showing to continue forward. Another ad released by Right to Rise Friday said that other candidates either “suck up” to Trump or “run away in fear,” painting Bush as the only candidate who has stood up to him.

The candidates aren’t just saving their attacks for the airwaves — they have also escalated their criticism of Trump at campaign stops across the state. Rubio tore into Trump on Thursday, questioning his judgment and character in one of his most direct critiques of the candidate yet.

“Donald Trump has zero foreign policy experience. Negotiating a hotel deal in another country is not foreign policy experience,” Rubio said in Okatie, S.C. Thursday morning.

“Even in our political culture, I teach my kids to be respectful. There are certain words you don’t say,” he added. “You turn on the TV and a leading presidential candidate is saying profanity from a stage. … All these things undermine what we teach our children.”

Cruz has, for his part, increasingly framed the race as one between himself and Trump. A Cruz aide said that the campaign will continue to undermine Trump’s conservative bona fides, painting him as part of the establishment ready to sell out conservatives to cut deals. The campaign will also continue its knocks on Trump for his support of eminent domain and making past campaign contributions to Democrats.

The Trump campaign has previously indicated it hopes to continue airing positive ads ahead of the primary. But the sheer number of ads released attacking Trump this week may make that difficult.

“You know what it is? You’ve got individuals who are running, and super PACs supporting those candidates, who have no vision for America,” said Trump campaign manager Corey Lewandowski. “Their only opportunity to win is to tear down candidates because they have no vision.”

“We’ve seen it before, it doesn’t work,” Lewandowski added. “They tried it in New Hampshire and it wasn’t successful and I don’t think it’s going to be successful in South Carolina.”

Lewandowski said that the campaign is focused on pushing a positive message but would not rule out running negative ads in the future.

Trump himself also continues to sound negative messages about his rivals. During the Baton Rouge event, Trump criticized Bush for being low-energy, dwindling in the polls and acting “like a child.” He made a joke about Rubio losing the last GOP debate. And he ripped apart Cruz’s latest attack ad, while explaining that eminent domain is actually a great way for average people to make a lot of money.

On Friday, ahead of a scheduled rally in Tampa, Trump fired off at least eight tweets attacking Bush and Cruz, plus a few going after the Club for Growth. He described Bush as “sleepy” and a “light weight” who has sunk to “false advertising- desperate and sad!” And Trump repeatedly questioned Cruz’s ethics.

“How can Ted Cruz be an Evangelical Christian when he lies so much and is so dishonest?” Trump tweeted Friday morning. Later in the day, he sent this warning: “If @TedCruz doesn’t clean up his act, stop cheating, & doing negative ads, I have standing to sue him for not being a natural born citizen.”

Philip Rucker, Katie Zezima and Sean Sullivan contributed to this report.