"As Congress has recognized since the Founding, a person born abroad to a U.S. citizen parent is generally a U.S. citizen from birth with no need for naturalization..."
Actually that's NOT true. At the time that John McCain was born, to American citizens but in the Panama Canal Zone, he was technically NOT a US citizen.
The history of this is rather interesting:
Until the Spanish American War and later WWI, there were very few cases where people were being born overseas to American parents and then later sought citizenship. However, in the few cases where this had occurred, that was a simple process by which the child would be granted citizenship via a perfunctory yet still legal 'naturalization' process.
Well the Spanish American War changed all that in that after the war the United States, for the first time, established permanent military bases overseas, most often Naval bases. And particularly with Naval bases, since they were extensive in nature and the overseas assignments could be lengthy, the military eventually started to allow families to go and be housed at these bases. Well as you can imagine, the rate of children being born outside the United States but to American citizens, suddenly took a big leap upwards and this issue of 'citizenship' finally came to a head in the mid-30's. Therefore a law was passed in Congress, but after John McCain had been born, that would once and for all make it legally indisputable that children born to American citizens in a foreign country, irrespective of their situation, military or otherwise, would AUTOMATICALLY be US citizens. And to make sure that this covered ALL the recently born children on these newly established military bases, the law was made to be retroactive back to the Spanish American War.
Well there was a problem with this since the Constitutions strictly states in Article I, Section 9:
No Bill of Attainder or ex post facto Law shall be passed.
Well someone took this to court a few years later and they ruled that with respect to this particular law, the Constitutional prohibition did not apply since it only would have if the change in a law deprived a person of life, liberty or personal property. In this case, there was only a positive benefit to the people impacted by the law, and thus John McCain became a 'natural born citizen' due to a law that removed the need for his parents to get him 'naturalized'. This is why, during his campaign for the presidency in 2008, he personally avoided making any comments about Obama's birth status because he knew that there was a big '*' on his bio when it came to his citizenship. Of course Sister Sarah never let that stop her from questioning the legitimacy of Obama's birth, part of what won her the title of being a 'rogue'.