Votes cast for a party aren't going to count.
If that was because the party concerned had screwed up then that would be incompetence. It's not though, its due to the actions of an opponent seeking to get votes not to count.
I guess I can't claim to know what North Carolina's ballots look like, but at least in the state I live in this isn't an issue. If you vote down the party line it will fill in the candidate for the party where available, and if there are multiple candidates in the same party running for the seat then you choose from them.