Btw, it says "No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution...". In 1765, the meaning of natural born was BOTH parents of the same nationality, actually the father determined nationality.
I can't believe that you would think it's Constitutional for the President to have dual citizenship.
So in your wacky world, Kim Jong Il or Fidel Castro could disqualify any Presidential candidate they wanted simply by unilaterally granting citizenship to them.