Kilgore was just a weak campaigner and debater. I don't think it's that complicated.
The fact Bolling and McDonnell won-- the latter without an NRA endorsement-- makes it clear Kilgore wasn't rejected for being a Republican. He was rejected for being Jerry Kilgore.
Frankly, he was notably weaker than Earley-- though Kaine is likewise weaker than Warner.
Internal GOP conflict in VA probably hurt Kilgore, but was not at all a deciding factor.
So you disagree that he wasnt conservative enough? I heard a lot of rumbling throughout the campaign regarding Kilgore not responding to a conservative groups survery regarding cutting taxes.