Your son CAN become President according to the Common Law Doctrine as outlined in Wong Kim Ark. The 14th Amendment was a declaratory Amendment according to the majority opinion in Wong Kim Ark.
The question presented by the record is whether a child born in the United States, of parents of Chinese descent, who, at the time of his birth, are subjects of the Emperor of China, but have a permanent domicil and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the Emperor of China, becomes at the time of his birth a citizen of the United States by virtue of the first clause of the Fourteenth Amendment of the Constitution...
And it was answered...
The evident intention, and the necessary effect, of the submission of this case to the decision of the court upon the facts agreed by the parties were to present for determination the single question stated at the beginning of this opinion, namely, whether a child born in the United States, of parent of Chinese descent, who, at the time of his birth, are subjects of the Emperor of China, but have a permanent domicil and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the Emperor of China, becomes at the time of his birth a citizen of the United States. For the reasons above stated, this court is of opinion that the question must be answered in the affirmative.
Be sure to note in that second snippet that the ...by virtue of the first clause of the Fourteenth Amendment of the Constitution... was omitted.
I ask of you as well...why would somebody claiming to be a natural born citizen cite a case based upon the 14th amendment making them a citizen by statute, not by nature?
Nonsense. WKA was not found to be a "natural born Citizen", only a "citizen."
And the state of Indiana case of Ankeny confirms that the WKA court did not find WKA to be a "natural born Citizen."