Oh, come on, your source is not intellectually honest. Wong Kim Ark very explicitly refers to a case (Minor v Hapersett) finding that “natural-born citizen” means “citizen by birth” in the context of the 14th amendment, and uses that definition to base its ruling.
My source is the holding in the Wong Kim Ark decision. The Court talks about "natural born citizen" all throughout it's dicta, but in it's holding, they simply call him "citizen."
Wong Kim Ark very explicitly refers to a case (Minor v Hapersett) finding that “natural-born citizen” means “citizen by birth” in the context of the 14th amendment, and uses that definition to base its ruling.
Dicta. They didn't put "natural born" in the holding.
Dicta is just musing and thinking out loud by the court. Only the Holding has legal relevance.