Should be fairly obvious.
Article II states the Pres must be NBC.
Amendment 14 for the first time adds a constitutional definition of who is an American citizen.
The Court needs to rule on whether the 14th's language has any bearing on what is meant by NBC in Article II.
Check out Minor vs. Happersatt for the interaction of the 14th and condition of a natural born Citizen. Or rather the lack there of.
The 14th Amendment did not change Article II, Section 1.
They did already in Minor v. Happersett and U.S. v. Wong Kim Ark:
In Minor v. Happersett, Chief Justice Waite, when construing, in behalf of the court, the very provision of the Fourteenth Amendment now in question, said: "The Constitution does not, in words, say who shall be natural-born citizens."
In construing the 14th amendment, the Constitution (of which the 14th amendment is a part) does NOT define natural-born citizenship. Minor made it very clear that persons who were already recognized as citizens (by virtue of being born in the country to citizen parents) did NOT need the 14th amendment to confer their citizenship.
... in our opinion, it did not need this amendment to give them that position. Before its adoption the Constitution of the United States did not in terms prescribe who should be citizens of the United States or of the several States, yet there were necessarily such citizens without such provision.
Further, the syllabus emphasizes that as much SINCE the adoption of the 14th amendment, that such persons are recognized as citizens because of the NBC criteria. This part of the syllabus is quoted verbatim in Ex Parte Lockwood.
2. In that sense, women, of born of citizen parents within the jurisdiction of the United States, have always been considered citizens of the United States, as much so before the adoption of the fourteenth amendment to the Constitution as since.
IOW, the 14th does not affect nor define natural-born citizenship. The Minor decision was unanimous, and because of their lack of dissent, Justice Gray noted in Wong Kim Ark that the Supreme Court was:
... committed to the view that all children born in the United States of citizens or subjects of foreign States were excluded from the operation of the first sentence of the Fourteenth Amendment ...
All children, born in the U.S. of citizen parents were EXCLUDED from the operation of the citizenship clause of the 14th amendment. In case there's any question, the definition of NBC was specifically offered to satisfy the meaning of the term in Article II:
This is apparent from the Constitution itself, for it provides [n6] that "no person except a natural-born citizen, or a citizen of the United States at the time of the adoption of the Constitution, shall be eligible to the office of President," [n7] and that Congress shall have power "to establish a uniform rule of naturalization." Thus new citizens may be born or they may be created by naturalization.
The Constitution does not, in words, say who shall be natural-born citizens. Resort must be had elsewhere to ascertain that. At common-law, with the nomenclature of which the framers of the Constitution were familiar, it was never doubted that all children born in a country of parents who were its citizens became themselves, upon their birth, citizens also. These were natives, or natural-born citizens, as distinguished from aliens or foreigners. Some authorities go further and include as citizens children born within the jurisdiction without reference to the citizenship of their [p168] parents. As to this class there have been doubts, but never as to the first.
Justice Waite gives two separate classes of how one might be recognized as a citizen by birth, but ONLY ONE was characterized as natural born citizens: all children born in the cuontry to citizen parents. As we all know, this precludes Obama from being a natural-born citizen, even if he were born in the Oval Office.