A late breaking poll has Hillary up by seven against Obama nationally among Democrats, this follows an earlier poll which also had Hillary up nationally. At this point, national poll numbers mean little—the majority of states have already voted—but they are signifiers of momentum. So, if Hillary were to beat expectations in Indiana and North Carolina these numbers could help turn around perceptions of the race.
Certainly, Bill Clinton was doing little to downplay expectations at his late night rally, suggesting that Hillary might even win in North Carolina. If she were to do so, the race would look very different on Wednesday morning.