The best experience for being Prez is being Prez. That is one reason the incumbent has an edge.

Next best, IMO, is experience as an executive - someone who is at the top, who makes decisions. This could be a Governor, a military officer, or a CEO of a major enterprise. After, this is the office of the Chief Executive.

Experience as VP is good for being VP again. But it may or may not be good prep for being POTUS. It depends on how involved the VP was in actual affairs and decisions. I heard Biden did not want to OK the mission to kill bin Laden. How does that make him qualified?

I think experience in congress is of little help. Better than nothing I suppose.

So, in which ways did you deem McCain and Palin unqualified?