Hey, I like Rudy too, but without the Conservative Christian vote (of which I am), ANY candidate is toast. Believe me, I would vote for Rudy over Hillary any day, but a lot of Christians just don't understand politics and that you MUST stop the Dims no matter how much don't like your choice on the right. They don't REALLY understand how dangerous the progressives are. All that to say, Rudy could not pull it off. Same reason Mitt will never win. Evangelicals, in mass, will never vote for a Mormon.
Not to mention, we are about to hand the Left the Hispanic vote. Without the far right any '08 Repub is a goner.
He would get so much more of the middle and he's so much more likable that he'd trounce Hillary, I think.
Still, you're right about Christian Conservatives, which is why I suggest going as VP first to prove to the people that he can be conservative.