David Greene has business news.

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.

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.

It took George Lucas more than two decades to bring the movie Red Tails to the screen. It was all the way back in the late '80s that the man behind Star Wars and Indiana Jones fell under the spell of another story of adventure, this one with real-life heroes — the African-American fighter pilots of World War II.

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.

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.

Saturday is South Carolina's Republican presidential primary. It's also the second anniversary of the Supreme Court's famous Citizens United decision.

That's the case that allows corporations to explicitly support or attack specific candidates. The day will be marked with attack ads — and protests.

The Republican presidential race has covered just three states so far. And superPACs linked to candidates Mitt Romney, Newt Gingrich, Rick Santorum and Ron Paul have spent a total of $20 million. They're feeding voters a heavy diet of negativity.

Transcript

DAVID GREENE, HOST:

As Mara just mentioned, the debate last night opened with a question about a claim made by Gingrich's ex-wife. Well, Marianne Gingrich gave her exclusive interview to ABC's "Nightline," putting the candidate's personal life in the spotlight once again. NPR's Tamara Keith has more.

TAMARA KEITH, BYLINE: The interview was incredibly hyped, in part because Marianne Gingrich has been silent so far on her ex-husband's presidential candidacy. This was her first television interview since their 1999 divorce.

On This week's media roundtable. we’ll discuss coverage of taxes and ongoing budget cuts in California. We’ll also talk about coverage of President Obama saying no, for now, to the Keystone Pipe line and the mass protests in Nigeria. We’ll be joined by the Sacramento Bee’s Phillip Reese, Mother Jones’ Kate Sheppard and freelance journalist Gillian Parker joins us from Nigeria. Join us at 10 or email feedback@yourcallradio.org. Where did you see the best reporting this week? It’s Your Call, with Rose Aguilar and you.