The fact that the Democrats are over-performing from 2012 is a bit surprising no? Given that was an already banner year.
The percentage of Democrats voting in early voting has been falling the last couple of days. There are two days of early voting data to be added, so I suspect they will be slightly below the 2012 percentage when early voting is complete.
Rasmussen says Hagan is winning 50% to 44% among those that have already voted. As of now, the Democrats make up 47.8% of the early voting so she running a couple of point ahead of the percentage of Democrats. In 2012, Democrats cast 44.2% of the ballots for the election (not just early voting).