With all the northeasterners moving to NC and bringing their leftist tendencies, I wouldn’t call NC “Strong R”. I’d more accurately call it “Tilt R”.
For the current "Strong R" setting, it is based on the 2016 election result where North Carolina went for Trump 50.5% - 46.8%. With an assumed 5% MOE, that translates into an 80.16% probability of the leader actually winning, which I put into the "Strong" category.
-PJ