There has been a considerable dearth of polling in South Carolina over the past month (since Sanders began to make his move). Most of the polling in South Carolina was at the end of October and beginning of November when Clinton was riding high from the first debate and her testimony before Congress on Benghazi.

During that time, many polls had Clinton up over 40 points on Sanders in South Carolina. A CBS News/YouGov poll released today (already diaried by slinkerwink) showed Clinton up 22 over Sanders (high MOE of about 9%). The same poll showed Clinton up 36 in December (a 14 point gain for Sanders) and Clinton up 47 points in November (a 25 point gain for Sanders). Even with the high MOE, this shows a Sanders surge starting sometime in early December. The surge is pretty evident in the Huffington Post tracker:

It is clear why Clinton ally and super PAC leader David Brock basically called Sanders a racist last week. In the November poll, Clinton lead Sanders 82% to 14% among African American voters (a whopping 68 point lead for Clinton). In the December poll, she lead 78% to 19% (a 59 point lead). In the January poll, she leads 76% to 22% (a 54 point lead). This means that Sanders has gained 14 points among African American voters during that time. Sanders is slowly winning over some African American voters while Clinton is losing them. Among white voters, Sanders went from losing them 42%-57% in November to winning them 60%-38% now (a 37 point gain for Sanders).

The point is not to argue that Sanders will win South Carolina, but that there is a surge happening in his direction right now. He does seem to be winning over some African American voters. We will have to wait for more polls to see if this continues.