Newt Gingrich's swift rise has been fueled by one thing above all — his forceful performances in the debates. And Thursday night, Gingrich was dominant from the start when he got the first question. It was about an explosive television interview with his ex-wife Marianne.

GOP presidential campaigns and superPACs have been spending millions of dollars on TV and radio advertising ahead of Saturday's South Carolina primary. While the negative superPAC ads air, the candidates are delivering a more positive message.

The Iowa Republican Party has certified the results of its caucuses earlier this month. Rick Santorum is 34 votes ahead, but the party will not declare a winner because there are missing results in eight precincts. Before the certification process, Mitt Romney had been declared the winner.

On the campaign trail, GOP presidential candidate Rick Santorum often discusses his opposition to abortion rights and gay marriage. That message served him well in Iowa with its large contingent of evangelical voters. Christian conservatives are also dominant in South Carolina, which votes Saturday. Santorum hopes to repeat his Iowa performance, but he's been struggling to keep pace in polls.

Renee Montagne has the Last Word in business.

David Greene has business news.

The last Republican presidential debate before Saturday's South Carolina primary was expected to be lively. It didn't disappoint.

It was clear, even before the four remaining candidates met on the stage in Charleston, SC, that at least three of them would face some fairly high-stakes moments that could change the course of the contest. The question going into the debate was would they be able to master those moments?

Whenever the late New York Times caricaturist Al Hirschfeld sketched Carol Channing — whether picturing her as an indomitable Dolly Levi, swathed in feathers and sequins, or as carbon-crazed Lorelei Lee, eyes sparkling like the diamonds that were that splendid creature's best friends — he always made her appear a creature composed entirely of lipstick, mascara and hairspray.

If you listen to commercial radio, this is not news: Katy Perry had a huge year. She went No.1 five times. She was the most played artist on the radio. But the record industry is so weird, it's hard to know whether this kind of success translates into huge amounts of money.

So we asked.

I walked over to Katy Perry's record label. She's on Capital, which is under EMI. I met Greg Thompson, executive vice president of marketing and promotion at EMI.

"Did you guys end up in the black?" I asked.