The U.S. Constitution is law. The definition is historical and based on natural law.
You want further information, see: Natural Born Citizen, and go through the archives.
http://naturalborncitizen.wordpress.com/
There you will find the facts why Obama never, ever wants his citizenship records to be examined in a court of law.
A child of immigrants can become President only if the parents became citizens BEFORE he/she is born.
For example, Donald Trump’s mother was Scottish. She naturalized years before he was born. So The Donald is a ‘natural born citizen’ and eligible to serve as President.
I’m sorry, please show me chapter and verse of US law that prevents Rubio and Jindal (or Obama, for that matter) from being considered natural born citizens. This is silly. Of course children of foreign diplomats are not natural born citizens, and children of parents who illegally cross our borders or overstay their visas shouldn’t be considered natural born citizens, but there is absolutely reason to deny natural born citizenship to those who have come here legally and are on the path to citizenship.