I’ll wait for some more polling before drawing any conclusions, but the most recent South Carolina poll by Insider Advantage has Romney ahead of Newt by 2 percentage points, via The Hill:

Despite a historic sweep of the first two nominating contests in the GOP field, Mitt Romney holds just a two percentage point lead in South Carolina, his smallest lead of 2012.

Romney is the favorite of 23 percent of South Carolina voters, narrowly edging Newt Gingrich’s 21 percent, according to the latest poll from Insider Advantage. Rick Santorum pulls 14 percent of Palmetto state voters, while Ron Paul rounds out the top four with 13 percent. Jon Huntsman’s seven percent and Rick Perry’s five percent trail the pack.

The numbers could indicate that Gingrich’s aggressive strategy – which has included controversial attacks on Mitt Romney’s business and abortion records – is gaining him traction by hurting the GOP frontrunner.

Other South Carolina polls are several days old and varied from Romney 3 points ahead to 18 points ahead.

Romney’s SuperPAC is spending heavily in SC, which may be a sign its internal polling is telling the same story.

(added) If you have not yet read Dan McLaughlin’s post, On Romney, Bain and Keeping Your Integrity, you need to.  It lays out a lot of what I have been saying about nominating someone whose primary claim to the presidency is his business experience without a full appreciation  of the political implications of that experience:

But just because the role of red-in-tooth-and-claw capitalists is a crucial and necessary one does not mean that they are likely to be popular candidates in today’s general election environment.  Criminal defense lawyers, for example may be crucially necessary to our system of justice, but if they have represented a lot of unpopular clients, they are not likely to be politically viable.  I continue to think that Romney’s business record is an under-explored political vulnerability (one Ted Kennedy used against Romney in 1994, but didn’t even use all the ads he cut) that the Democrats will exploit ruthlessly.  And Romney’s existing defenses of that record are fairly weak.  We should not be caught unawares by this in the summer and fall when it’s too late to pick another candidate.  In many ways, it’s like the swift boat story.

Update: Corrected, here’s PPP SC polling, not yet completed:

The prior PPP poll had Romney up by 7.