ABC News

One of the biggest headlines of the Republican primary race so far - and the point Stephen Colbert is trying to make with his satirical campaign - is the story of SuperPACs.

Take Newt Gingrich. Gingrich's poll numbers in Iowa were competitive until these shadowy groups started attacking him with TV ads. Nearly half the political ads run in Iowa  - and they saturated the airwaves - were negative ads against Gingrich, according to the Campaign Media Analysis Group. Many of those attack ads were put on the air by the SuperPAC called Restore Our Future, which is run by former Mitt Romney aides and supports his candidacy.

Because of U.S. campaign finance laws, the Romney-supporting SuperPAC can't have any official contact with the Romney campaign, but we did ask Romney if he believes the SuperPACs should go away.

"I think the campaign finances laws that we have in this country are terribly counterproductive," Romney told us on the campaign trail earlier this month.  "They limit how much money campaigns can raise and yet allow other entities to raise unlimited amounts."  Romney added, "The campaigns should be the ones responsible for their own ads."

But when pressed on why he doesn't publicly pressure SuperPACs to stop the negative ads, Romney responded, "The idea of having campaigns point out distinctions between candidates is a good idea to get underway right now."  Romney adding, "The heat we have in the kitchen right now is nothing compared to what's going to happen with Obama's hell's kitchen."

The ad war tables have turned somewhat in South Carolina, where a SuperPAC that supports Gingrich- and counts Gingrich's former aides among its advisers - is spending more than $3 million on attack ads against Romney and his record as head of Bain Capital.  This latest round of SuperPAC ads have had an unintended consequence.  While targeting Romney's record at Bain in an effort to keep Gingrich's campaign alive, many leading conservative voices have come out defending Romney from the attacks arguing Republicans should not be attacking capitalism and 'free enterprise.'

Sen. John McCain has endorsed Romney to win the primary.  He's also the senator who championed the McCain-Feingold campaign finance law that was largely gutted by the Supreme Court's Citizens United decision.

On the campaign trail, we asked McCain about the ads from the SuperPAC that supports Romney.  He told us these SuperPACs will "destroy the political process," and predicted "scandal" because of them.

We asked him why he or Governor Romney won't publicly pressure these SuperPACs to take the ads down.

Here's what he said:

McCain: Because they won't stop. Because they won't stop. I mean, as long as unlimited amounts of money are there, there not attributable to the candidate, it's going to happen. I mean, it's just, it is the way it is. We had campaign contribution limitations for a reason and the United States Supreme Court basically did away with all of that and we're going to pay a heavy price for that and I also guarantee you that there will be scandals sooner or later.

ABC's Z. Byron Wolf contributed to this report.