Stay focused on his message. Answer other questions, but turn everything back to his theme: Davis' failed leadership.
Set loose pit bills unaffiliated with his campaign to attack Davis's individual failings (Oracle, fundraising, "pay-to-play", energy, education, economy, taxes, etc.)
Be emphatic but not angry in the debates; watch Kennedy and Reagan.
Get Davis angry.
If Davis loses it, he'll REALLY lose it. Apparently, it's not all that hard. The guy is insane.