In each state there are counties that help predict which way the state is going to go in the election.
In North Carolina, Wake County serves as a bellwether for rough predictions. It is the largest county in the state and right where Raleigh is located. CNN did an analysis of the county in 2008 and 2012 and discovered an interesting trend.
There is no doubt the county will go Democratic considering its demographics and being in the heart of the Research Triangle, but what is important is the turnout rate. In 2008, then-Senator Obama won the county by 63,000 votes (and won the state). In 2012, President Obama only won by 54,000 votes. For a state that’s going to be a close one, an almost extra 10,000 votes is critical for Hillary Clinton to win.
The key to bring up the voter turnout will be turn out the African American voters in the county. However, being located in the Research Triangle, the college educated whites have become paramount as well. If Hillary Clinton can win both of these demographics by a large enough margin in the county, then her chances look good for North Carolina to turn blue.
NPR also points out the county in the Western part of the state that has voted for the winner in the last three presidential election cycles and last three Senate elections. It is Watauga County located right next to the Tennessee boarder. While certainly not a very populous county, home to Boone though, it has served as a predictor for the last several winners.