NC has always been the most progressive former Confederate state. That is still the case today, when a fair number of far Leftists can be found in the WNC and the Triangle areas. This combined with a number of anxious Dixiecrats being turned off by Clinton's focus on social issues gave Sanders his best performance in the former Confederate states.
Tennessee says hello with Estes Kefauver, Gore Sr, Ross Bass, Frank Clement, and the early history of Eastern Tennessee in general.
Not to mention it [NC] voted rightwards of Florida and barely leftwards of Georgia...the latter of which Hillary did pretty much nothing in.
Seems to me the result was that Bernie did diddly-squat in The South around Super Tuesday and by the time NC hit, he upped his game in general once Oklahoma and Kansas went to him and proved he had more chance.
I think the likely answer is that NC has more white progressives than most other southern states, except for Virginia. Considering the racial lines the primary fell along, that probably helped him.
Virginia voted much earlier than North Carolina, at a time when Bernie's poll numbers were worse nationally. (He was polling at a 20 point deficit when voting started in the early states, and gradually evened it out by the end, but the delegate lead Clinton amassed in early states was locked in). This could help to explain his worse performance there. In the appalachia states, KY and WV, the lower percentage of black voters and later voting date once again improved his performance compared to the rest of the south.
