Your proof is in Article 2 Section 1. There are two conditions for being president: (1) "natural born Citizen", or (2) Citizen of the United States, at the time of the Adoption of this Constitution. What you are doing is removing the phrase "at the time of the Adoption of this Constitution". You cannot simply ignore words that are inconvenient. Since anyone under condition (2) is now presumably dead, that leaves "natural born Citizen", and the 14th Amendment does not define that term.