A citizen is not necessarily a Natural born citizen.
Only a child born of 2 US citizen parents can be a Natural born citizen.
That is the sole defining criteria for a Natural born citizen.
It is about sole allegiance and loyalty to this Nation alone.
Only a Natural born citizen can meet this criteria.
Congress agreed that John McCain was a Natural born citizen despite his birth in Panama, because McCain had 2 US citizen parents.
The 14th Amendment creates born citizens regardless of the place of birth or the nationality of the parents.
A child born in any country in the world who has a US parent is a US citizen at birth, as well as a citizen of the country in which they were born, in most cases.
They are born with dual citizenship.
A child born in the US who has one, or even NO US PARENT, is a US citizen at birth, as well as a citizen of the country of which their parents were citizens of.
Those children are born with dual citizenship as well.
Either way, Obama is not a Natural born citizen.
It is really not that hard to understand.