His parents were born in the British North American colonies and where thus natural born British Subjects. But they became citizens of the US upon the Independence of the United States, and were certainly citizens when he was born. So yes he had two citizen parents. He was born in the country. So he was a natural born citizen.
Is it logical..Obama must meet the same criteria as Polk to be considered a natural born citizen. Polk is the first natural born citizen elected President.
The author is a constitutional scholar. Something is wrong.
This book is difficult to access on the internet.