GUY RAZ, HOST:
It's WEEKENDS on ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.
(SOUNDBITE OF POLITICAL AD)
UNIDENTIFIED MAN #1: A story of greed, playing the system for a quick buck, a group of corporate raiders led by Mitt Romney, more ruthless than Wall Street.
RAZ: That's part of an anti-Mitt Romney ad now running in South Carolina. The video is being distributed by pro-Newt Gingrich superPAC. And its message may be a sign of a growing philosophical split among the GOP candidates.