The NC state legislature is probably so gerrymandered that a D+7 lead will not be enough to flip it. The dubious claims made about gerrymandering making it extremely hard for Dems flipping the US House, they are largely applicable in regards to NC's state legislature.
The gerrymanders of VA and WI have not been holding out in these special legislative elections, so there is a good chance the Dems might be able to break them. I think NC voters have just had it with the GOP
I'm really curious what a D+7 result would do to the legislature, but I think I have to agree with TimTurner in that flipping it with just D+7 doesn't seem possible. There is also precedent for this. Michigan's state House didn't flip in 2012 even with an almost D+8 popular vote win. Republicans walked away with a comfortable if not slimmer majority. The only difference between an R+8 pv in 2010 and a D+8 win in 2012 in Michigan was Democrats gaining 4 seats.
That's literally all they got with wave-like numbers.To use a more recent example, in Virginia 2017, Democrats flipped only one or two Trump seats with a 9 point PV win
(skewed maybe by more seats w/o GOP candidates). Granted, Democrats flipped 15 seats, but almost all of them were Clinton seats. In order to flip the NC GA, Democrats would have to flip dozens of Trump seats. It's hard to see that happening, tbh.