I’m unclear why this was a revelation to you.
AFAIK everybody is in agreement that NBC status can only be acquired at birth.
The debate is between all “citizens at birth” being NBC, and NBC being a subset of “citizen at birth.”
Using the first definition, there are two categories of US citizens: NBC/CAB and naturalized.
With the second, there are three: naturalized, NBC, and CAB but not NBC.
IMO there are legitimate arguments for Obama falling into either of the second two categories (assuming there’s a difference). Which is why we need a Supreme Court ruling.
Another example is the 2nd amendment. Rather than just reading the content , look WHERE it is in the overall structure outline of the document. Just another one of those aspects that i never hear used in argument.