Common misconceptions all around.
It's not that being a citizen of another country that is supposed to disqualify you from being the POTUS, but instead not being a "Natural Born" citizen.
Article II Section 1 Clause 5:
>No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States.
What does natural-born mean exactly? That's a bit more complicated.
Potentially this candidate of yours is more eligible to run for president than Ted Cruz.