I don't see why he'd have such a hard time winning the primary. He didn't win over Democrats so overwhelmingly because he was more moderate (on the contrary, he was actually probably the more conservative candidate in that race), but because his opponent was an ass. It's not like he's done anything to piss off the base.
He won over Democrats because he played hard to rest of the district (including higher Democratic Athens county) vs. Columbia County politics. In a special election, turnout can often mean everything happen, and his margins in those situations carried him. But in a GOP primary, Columbia County will dominate.
