The GOP-e has their person picked already, and Hagan is ahead of that person in the polls. There are several GOP hopeful candidates that GOP voters like more than the GOP-e choice, but the GOP is not interested in what the voters want... particularly GOP voters, and even more particularly, conservative GOP voters.
...Which is why I believe RINO behind-the-scenes treachery will doom any chances of taking over the Senate. The GOP-e would rather see an easy win for a conservative in the general election morph into a sour defeat, just for the momentary satisfaction of saying, "See? We told you only moderates can get elected now!"