Citizen at birth, with the caveat that the parents are Citizens themselves, whether they were naturalized or were already Natural Born Citizens themselves.
Thus the desire by foreigners/aliens to become a US Citizen.
Their American born children will be natural born Citizens, even though they themselves never will be.
If their children were foreign born then their children will be NBC's.
Don't forget, positive law can't supersede natural law and make someone a NBC.
JMO, YMMV