on Mitch Daniels being a no
Something that doesn't get much attention: Daniels, among other potential GOP candidates, would have had a rather tricky line to take regarding the deficit. During both the primary and the general election, he'd be saying all sorts of things about how serious he is on the deficit. And Democrats and others would point out his role at OMB in the Bush Administration (from the beginning until June 2003) -- i.e., tax cuts for the rich, and the Iraq and Afghanistan wars. See more from Jamelle Bouie.
This hypocrisy hasn't been much of a problem for him (or others) with a punditocracy that's obsessed with him, but in a general election campaign, I think it would certainly be at least a moderate problem.