Newt Gingrich is now leading Mitt Romney in most South Carolina primary polling, certainly at least in part as a result of the massive and well funded negative TV campaign against Romney. Of course its also true that most South Carolina Republican voters are a lot more conservative than Romney, and thus the Gingrich camp can reasonably argue that they've simply been helping South Carolinians figure out who the "more conservative candidate" is in this campaign.
It's still difficult to see how even a narrow victory by Gingrich could derail Romney's likely victory in the Republican primary, but it'll certainly make for a more interesting horse race.
