[philman_36]

One need only be born a U.S. citizen under U.S. law (which should always be in accordance with natural law) to be a natural born citizen.
What US law in particular are you talking about?

So where in the U.S. Constitution does it mention any fourth category of citizenship?
Have I claimed anywhere on this thread that the U.S. Constitution mentions a fourth type or category of citizen?

[allmendream]

You need it to - otherwise there are only TWO categories currently - natural born and naturalized. Where do you find another category mentioned?

What U.S. law am I talking about? ALL U.S. law concerning granting citizenship at birth - of course. This is not avoiding answering your question - it is answering it directly.

One need not have any citizen parents at the time of birth to be a U.S. citizen at birth - as is the case with Marco Rubio - whose parents were legal residents of these United States.

If there are currently only two types of U.S citizen, then a U.S. citizen at birth is a natural born citizen; and the other category must be naturalized via a legal process and sworn oaths of allegiance as outlined under Congressional power to adopt a uniform rule of naturalization.