NC. I don't think it gets that far though. Landrieu and Begich are incumbents in good position to win reelection, and Grimes running a competitive race against the minority leader is an excellent diversion in the news cycle to keep attention away from them.
Here are the seats that are most likely to flip
South Dakota
West Virginia
Arkansas
Louisiana
Alaska
Montana
KY*
North Carolina
Ga**
*Will be Higher if Grimes makes the race more statewide and not national
**Will be Higher if Reps nominate a right wing nut and Dems Nominate a good candidate.
This is a good list, even though Schweitzer is a much better candidate than Hagan.