Nonsense. He was naturalized at birth by the Citizenship act of 1934. (and subsequent variations thereof)
Congress SET the act to apply at birth. Of COURSE it applies at birth. Congress has no power beyond naturalization.
Here, read the D@mned thing! It even SAYS it's an act of "naturalization."
Ted Cruz is a "naturalized" citizen, who was "naturalized at birth", by an act of congress.
My money is on the courts going with what follows when Ted Cruz’s eligibility status is adjudicated. It is also likely that the Senate will pass a Sense of the Senate Resolution clearing him to run like the one they passed for McCain.
“The following shall be nationals and citizens of the United States at birth:
(g) a person born outside the geographical limits of the United States and its outlying possessions of parents one of whom is an alien, and the other a citizen of the United States who, prior to the birth of such person, was physically present in the United States or its outlying possessions for a period or periods totaling not less than five years, at least two of which were after attaining the age of fourteen years...”
US Code, Title 8, Section 1401
http://www.law.cornell.edu/uscode/text/8/1401