If you compare 2000 to 2004 for George W. Bush, North Carolina is one of only 3 states where his share of the vote went down (others being Vermont and South Dakota). Slight, but I wouldn't've bet on NC being the third worst state when compared to 2000. I don't believe Edwards had much to deal with it either. Non-Democrats in this state don't care for him.
Maybe, but the DNC spent far more in NC than in any similar state, right up until the final weeks of the campaign in the hope that Edwards' presence on the ticket would make the state competitive (something early polls suggested was possible)... I'm not denying the state has seen a slow trend towards the Dems in some areas, but the '04 results is distorted as a result of the Dem's targeting of the state.