Can't someone share the same "moral compass" as you and not be nearly as good at following that compass?

Yes, it's only a starting point, and I've been dissapointed in a lot of the choices Bush has made.

Or, to be more specific, how can you blindly trust Bush's motivation for the war if you don't know how good he is at sticking to those morals when it comes time to make decisions?

In fact I really don't know what his motive for the war really was (does anybody), though I think I know what it wasn't.

Aren't some Christians better at adhering to their faith than others?

Again, yes and if there were a better option I'd take it. However, I'll still take the person who starts at the right point and makes mistakes over someone who's starting at the wrong place to begin with.