Huh? If there is no citizenship law then there are no citizens at all. Hillary Clinton thanks you for your support.
So what man-made (positive) law makes NATURAL born Citizens - citizens?
You can be born a citizen. Like the people of Puerto Rico.
And that makes you a BORN citizen - a superset of natural born citizens.
But the people of Puerto Rico need a to be citizens of the US. They are collectively naturalized. They are LEGALLY NATURALIZED citizens - though the vast majority of them have never gone through any ‘naturalization process’. The process is based on the law and the law says - born in Puerto Rico - you are collectively NATURALIZED - AT birth.
Any and all laws passed by Congress that MAKE someone a citizen are a form of naturalization. Congress is ONLY charged with laws for the NATURALIZATION of citizens. So ANY law Congress makes granting citizenship is a form of naturalization. Natural born Citizens are not citizens due to some law made up by Congress. They are - natural.