I agree with this. Tillis won by slightly less than 1.6 percentage points in 2014, which was a Republican wave year, and North Carolina has been a closely divided swing state for years. It's not surprising that in this kind of national environment, it would lean towards the Democrats.
Or -- alternative take: Tillis won by slightly less than 1.6 percentage points in 2014 because the state has zoomed leftward.
This does make Deborah Ross' showing look really pathetic, though.
You could be right. But I still think that the national environment, more than anything else, is influencing the trajectory and the eventual outcome of this race. Cunningham isn't the strongest candidate Democrats could have run here, and is benefitting from the same external factors that are driving the Biden lead here. To say nothing of the fact that Tillis has never been popular and has always had weaknesses with the Republican base.