Wikipedia has an interesting discussion on this, though their facts are not verified.
http://en.wikipedia.org/wiki/Natural-born_citizen
It doesn’t appear to me that McCain is eligible to be president. The point is moot now in his case, since he won’t run again for that office, but it needs to be answered.
There really is no definition of “natural born” citizen in the constitution unless it can be inferred from the wording. If the Supreme Court does hear these cases, this is their only possible “out”. I just don’t think they will take that “out”.
One question arises when only one parent is a U.S. citizen and the residency conditions of that one parent. i.e. A U.S. citizen moves to europe and lives there for several years, marries a european spouse and they have a child.
Though the person moving to europe from the U.S. may still be a U.S. citizen (never seeking immigration status in the new country)case law has never really tested whether that persons child would be a Natural born citizen. Everything we hear regarding situations like that is PURE speculation until such time that Congress addresses the issue in legislation or the USSC decides case law explicit to those conditions.