Gerrymandering works by packing a bunch of opposition voters into a few districts, so as to make the remaining districts slightly safer for the majority party. So the "punishment" for opposition voters is having a congressman more to their liking than the one who would represent them otherwise.
And considering three of the North Carolina districts are listed as competitive on Cook and Sabato, I do not think legislative redistricting is the all-powerful tactic of totalitarianism that you think it is.
This is not to say that I approve of gerrymandering. Districts ought to be as contiguous as possible, mostly reflect county lines, and completely disregard race. But I cannot pretend that deviation from that is unconstitutional just because I do not like it.
The punishment for the opposition voter is permanent minority status in the state's delegation, even if they win a majority of votes in the state.
Further, in a first past the post system like the US, the difference between a Democrat from a D+20 district and a Democrat from a D+5 district can be very small or even unnoticeable.
