Notice that the opinion referred to speaks of a “citizen,” not a “natural born citizen.” The two things are distinct. As has been repeatedly pointed out in the actual scholarship and is known to anyone competent who has actually properly researched the issue, the phrase “natural born citizen” would not have been used in Article II had the framers meant “citizen.” The specific phrase “natural born citizen” was used on purpose had a specific meaning at the time. It is true that in the opinion of which you speak its says, as you say, that such a one is as much a “citizen” as one who is a naturally born citizen but it does not say that such a one is a “natural born citizen.” One of the most commonly cited sources of the time for the phrase “natural born citizen,” is Vattel. You should actually learn to do research before calling people out based on error and lack of knowledge and certainly refrain from accusations that are ill founded.
"The child of an alien, if born in the country, is as much a citizen as the natural born child of a citizen, and by operation of the same principle. "
The phrase, "as much a citizen" means that the person in question is "as much" a natural born citizen as a person who had two U.S. citizen parents.
"As much as" means "Equal To" and equal to means the very same.
Moreover, the Justices did not say "if born in the country, is as much a citizen as the natural born child of two citizens....."
Instead, they said "if born in the country, is as much a citizen as the natural born child of a citizen..."
Obama has one parent who was a citizen.