He was born in Miami, Florida. He's a Natural Born Citizen per the Constitution.
Nobody's buying that birther crap.
Being born in Miami makes him a citizen. It does not make him a Natural Born Citizen.
The greatest service Rubio could perform for his country would be to say: I want to stop all speculation that I am running for President—because, like the current occupant of the White House, I am not eligible to hold the office of President.