There has never been such a ruling. The closest was U.S. v. Wong Kim Ark which ruled that those born in the U.S. to permanently domiciled aliens were U.S. citizens at birth.
Note, though, that Gray declined to specifically rule Ark a 'natural born citizen.'
I think it’s hilarious you somehow hold all the following, and contradictory positions.
1. Cruz is a natural born citizen and eligible
2. Obama is not a natural born citizen and eligible
3. Birthright citizenship does not exist.
Please explain to me how all three can be true at the same time. It’s impossible.