Actually, having checked, the Davis seat is Kerry plus 7.5%, and the Cunningham seat is Bush plus 11% on checking. So the Davis seat is more marginal on paper, but not right now, no way, Jose, given the climate and the Dem incumbency factor.
I'm under no illusions of us taking back the Davis seat at the current time, only that I would support Bilbray if he attempted to challenge Davis. As I said, in Dem-leaning districts, the Republicans ought to recruit wealthy candidates who can self-fund (after all, buying Senate seats in more competitive areas is the Dems M.O.).