As for McCain, there has been disagreement as to whether he was born in the Canal Zone or in Colon, Panama. If it were the Canal Zone, there would be no problem. (The McCain birth certificate posted over the Internet - indicating he was born in Panama - has been shown be FReeper Polarik to be a fraud, likely posted by a Democrat lackey.)
Well I appreciate Polarik but in this case, he is probably not correct. That Birth Certificate is in general circulation in the political community and the McCain people say it is a true and correct certificate of the original record.
I don't want a lot of further argument on this point but if Obama did get kicked out before the end of his term, McCain's status might make a difference. There really isn't much room for legal doubt or argument that McCain doesn't pass either.
It wouldn't make any difference whether he was born in the Zone or not because the Zone was part of Panama and even if McCain had been born in the Zone, he was still subject to Panamanian sovereignty from birth and thus flunks the Natural Born test.
Further, McCain had another problem--it has been assumed by people who just pick the USCA off the shelf that McCain in fact also became a US citizen when he came down the shute--however people assume that because the legislative history is not fully set forth; turns out that the statute on which McCain relies for citizenship was enacted after his birth without a retroactive application clause.
And he was not born in the Canal Zone either.
As for Goldwater, there were apparently lots of people in Mexico who were already arguing that part of Arizona was really part of Mexico; that claim existing prior to statehood might theoretically have been a basis for claim of sovereignty which would have barred Goldwater. I think that would have been a stretch--I think Goldwater probably would have been held eligible if elected; but apparently there was an active argument by the Dems.