” a child be born of foreign parents, it is an alien”
Anchor babies aside, that defintion fits precisely with our law saying a person (such as John McCain) born in another country to US citizen parents, is a NBC of the USA. It can not be both ways, one born is either a citizen of the country born in or not decible by parentage.
I'm not sure if you read my post completely in which the above quote by Blackstone, was stated to be part of French and not English law.
Also, even if that statement was part of our law, then it wouldn't apply to John McCain since whether he is regarded as an alien in Panama is irrelevant to how he is treated under US law.