The 14th Amendment makes it quite clear that there a two kinds of citizens:

"Born".....on American soil; and

"Naturalized"......made a U.S. citizen thru legal immigration and citizenship processing.

Marco Rubio was born on American soil and has been a citizen since the moment of his birth. He was not "naturalized" later by legal processes.

14th Amendment, Section 1. All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.