Berger has been the driving force behind much of the most conservative legislation that has come out of North Carolina's statehouse, along with the man he'd be facing in a primary if he does run for Senate, North Carolina state House Speaker Thom Tillis (R). Tillis is the only major candidate who's announced against Hagan at this point, though the field is expected to grow. Charlotte-area pastor Mark Harris (R) is also expected to jump into the race in the next few weeks.
Hagan is a top GOP target this election cycle, and the battle for her seat could be the tipping point for Senate control. But so far it's unclear whether the GOP will be able to find a tough enough candidate to defeat her.