A biting 60-second cartoon and a controversial 28-minute movie are just two reasons South Carolina is no place for thin-skinned presidential candidates this week.

Ahead of Saturday’s primary, the state’s airwaves are packed with attack ads not only from the official campaigns, but also - and especially - from super PACs that have spent millions of dollars for South Carolina alone.

Attack ads aren’t novel, but South Carolina combines a narrowed GOP field - front-runner Mitt Romney is now battling just four major rivals, all furiously trying to keep him from winning his third straight primary or caucus - with the relatively new super PACs.

The super PACs, created after federal court decisions in 2010, are allowed to receive unlimited campaign contributions from corporations, labor unions and individual donors. Traditional political action committees and candidates’ campaigns may receive only limited contributions.

Super PACs, which according to federal records have spent at least $6 million on South Carolina’s primary so far and $26 million on the 2012 presidential race overall, aren’t allowed to coordinate with candidates’ campaigns. This has sometimes led candidates to shrug their shoulders at rivals’ complaints about the ads’ accuracy, asserting that they have no control over the super PACs that support them and can’t legally tell them directly to make any changes.

Here is just a sampling of the attack ads that South Carolinians are seeing this week:

Target: Romney
From: Pro-Gingrich super PAC Winning Our Future
Title: “Obama’s Dream Debate, Part I” 

A super PAC supporting former House Speaker Newt Gingrich released on Wednesday a cartoon TV ad that imagines - in no way favorable to Romney - a debate between President Barack Obama and the former Massachusetts governor.

In the cartoon, an animated Obama says that he agreed with many of the positions Romney took during his gubernatorial stint, including those on abortion rights, gun control and universal health care.

"And on health care, well, I was so inspired by Romneycare that I nationalized it and called it Obamacare," the fictional Obama says.

The cartoon Obama contends that Romney changed his positions when he became a presidential candidate. A bumbling faux Romney doesn't manage anything beyond "hold on," "but I" and "whoa, whoa."

"I agreed with Gov. Romney on many things. But this presidential candidate Romney, I don't even know the guy. Then again, he doesn't seem to know himself," the cartoon president says.

Target: Romney
From: Pro-Gingrich super PAC Winning Our Future
Title: "When Mitt Romney Came to Town" or "King of Bain"

This nearly half-hour video, which stirred controversy when it was released last week, attacks Romney's time as CEO of the private equity firm Bain Capital. It depicts Romney as a greedy executive who caused mass job losses when the corporation bought and streamlined four particular companies.

Romney has stressed that while some of the companies that Bain invested in didn't end up a success, many did. He claims that four companies that Bain invested in under his leadership created 120,000 jobs. CNNMoney and Fortune have reported such claims are questionable because Bain doesn't track job creation numbers.

GOP critics of the ad characterized it as a form of class warfare. Gingrich himself publicly called on the group to fix inaccuracies in the film, though he did not mention any specific errors.

Target: Gingrich

From: Pro-Romney super PAC Restore Our Future
Title: "Desperate"

This ad lashes out at Gingrich for unspecified attacks on Romney and contends that Gingrich "attacks because he has more baggage than the airlines."

It has an image of Gingrich standing at a fictional “Political Baggage Claim,” as various suitcases roll past him. Among other things, the ad highlights a $300,000 penalty he had to pay following an ethics investigation when he was in Congress.

In 1997, the House voted to reprimand Gingrich. He was ordered to pay a $300,000 penalty for failing to ensure the tax-deductible charitable contributions that financed a college course he taught did not violate federal tax law and for giving the House ethics committee false information. Three years later, the Internal Revenue Service cleared the organizations involved of possible tax violations.

Gingrich defended his ethics record last year.

"We turned over a million pages of material. We had a huge report. The total - 83 charges were repudiated as false. The one mistake we made was a letter written by a lawyer that I didn't read carefully enough," he said.

Target: Former U.S. Sen. Rick Santorum of Pennsylvania

From: Pro-Romney super PAC Restore Our Future
Title: "Facts"

This ad asserts that Obama "knows four facts about Santorum that you don't," including that Santorum voted:

- "for billions in wasteful pork";
- "for the Bridge to Nowhere, a teapot museum (and) even an indoor rainforest";
- "to raise the (federal) debt limit five times";
- and "to let convicted felons vote."

In Monday's GOP presidential debate in South Carolina, Santorum criticized the ad for that last point. He said he did vote to allow felons to have restored voting rights once they completed their sentence. But he pointed out that the ad shows a man in a prison jumpsuit, which he says incorrectly insinuates that he wanted felons to be able to vote from prison.

On Wednesday, the same super PAC released a similar ad, criticizing Santorum about the debt limit, earmarks and the teapot museum. But it made no mention of felons' voting rights.

Target: Romney, Gingrich and Santorum
From: U.S. Rep. Ron Paul's presidential campaign
Title: "Three of a kind"

Paul's campaign takes on most of his rivals in this ad, calling Gingrich a serial hypocrite, Santorum a counterfeit conservative and Romney a "flip-flopper who's been on all sides."

CNN's Robert Yoon, Tom Cohen, Alan Silverleib, Ashley Killough, Shawna Shepherd, Rachel Streitfeld, Jason Hanna and the CNN Wire staff contributed to this report.