When Jimmy Carter and George H.W. Bush were up for re-election, they didn't improve on their percentages in any state. The opposite is true: George W. Bush only lost ground in three states (South Dakota, Vermont and yes, North Carolina, by 0.01%) as he won a second term in 2004. Other factors don't bode well for Obama to improve upon his 2008 performance in the Tarheel State: the state's Democratic governor, Bev Perdue, has struggled with low approval ratings and faces the likelihood of a tough challenge from former Charlotte Mayor Pat McCrory. The state's most prominent politician, former presidential candidate John Edwards, may be on trial for campaign finance around the time of the president's re-election campaign. And our friends at Smart Politics have analyzed the data, and concluded there's historically no boost for candidates in the state where their party holds the convention. Obama's re-election team surely believes the president has the demographics on his side in competing for North Carolina - and they're right about the trend lines. But he'll have to buck historical trends, not to mention a lousy economy, if he hopes to win it again.