By definition—and one would think common sense—legal tourists here to enjoy Disneyland and illegal immigrants who broke into the country clearly do not fall under this blanket of allegiance-owing jurisdiction. Accordingly, their giving birth on American soil does not make their children citizens.
Congress has the plenary power to make policy judgments to determine naturalization requirements and immigration levels— a power bestowed upon Congress by the founders of the republic.
Why is this important?
WE NEED TO LIVE IN A DEMOCRACY NOT A CAPITALIST COUNTRY!