Polling Southern primaries tends to be difficult, and Insider Advantage does at least a competent job at it. But their new poll showing Clinton 2 points ahead of Barack Obama is a little odd. Clinton leads 54-33 among white voters, a result that is not great news for Obama but is fairly consistent with other polling in the state, including polls where he has a double-digit lead.
The difference is in the black vote. Firstly, Obama leads that vote "only" 64-20, with 15% undecided, a vote he has won 83-15 over the course of the primary season. Secondly, the poll shows only 25% of the turnout being black, which would be a very low result. The general rule of thumb is that black turnout equals about 150% of a state's African-American population, which in North Carolina's case would work out to 33%.
Of course it's always possible that there has been a black backlash of sorts against Obama's distancing himself from Jeremiah Wright. But Insider Advantage has a history of weird things going on in their cross-tabular reporting. They also have a history, not unlike ARG, of publishing weird results in the run-up to the primaries (Clinton +33 in Tennessee, Clinton +8 and Edwards +7 over Obama in Iowa) and then fixing those results with more reasonable looking results just before the primary actually takes place. One disadvantage of our pollster rating methodology is that we only look at the last poll before an election. Insider Advantage could be into something here, but if not, we might need to revisit that assumption.