In my opinion Cruz is qualified, but not Jindal. Don’t know about Rubio. If his parents were citizens when he was born, then he should qualify.
It doesn't matter anymore, because "We aren't in Kansas anymore Toto."
But for what it's worth, the "Natural", in "Natural Born Citizen" comes from "Natural Law", which was a legal philosophy that guided the founders in creating this nation. It is specifically referred to in the Declaration of Independence as "the laws of nature, and of nature's God...".
The US Constitution did not create citizens. Citizens were created by the Declaration of Independence. Court cases of the time period specifically refer to "July 4, 1776" as the day on which American citizenship began.
Only those born after that date could be "Natural Born".
The point here is that the guiding philosophy underpinning the Declaration of Independence should apply, not subsequent man made laws that are inconsistent with nature.
But like I said, that ship has sailed. Now anytime Congress naturalizes a class of people, (Such as the foreign born children of a single American parent), modern legal people are going to call them "natural born" when in fact they are not. They are "naturalized by statute."
Congress cannot change the rules of natural born citizens, but they can change the rules on anyone who is a citizen as a result of a law passed by congress.
Neither of Rubio's parents were United States Citizens at the time of his birth in Miami. Cruz was born in a foreign land to a foreign father. Like Rubio and Jindal, Cruz is not even close to being a natural born Citizen.