The law in effect at the time of McCain's birth:
1934 Act of May 24, 1934, Section 1, 48 Stat. 797.
"Any child hereafter born out of the limits and jurisdiction of the United States, whose father or mother or both at the time of birth of such child is a citizen of the United States, is declared to be a citizen of the United States: but the rights of citizenship shall not descend to any such child unless the citizen father or citizen mother, as the case may be, has resided in the United States previous to the birth of such child. In cases where one of the parents is an alien, the right of citizenship shall not descend unless the child comes to the United States and resides therein for at least five years continuously immediately previous to his eighteenth birthday, and unless, within six months after the child's twenty-first birthday, he or she shall take an oath of allegiance to the United States of America as prescribed by the Bureau of Naturalization."
Both of McCain's parents were citizens. Do you want that in all caps, then?
Any updates on this case.