Rubio was born in florida, the big question is about his parents. They were cuban exiles but Rubio has not said if they became US citizens.
Makes no difference. Rubio was born here ergo he is a US citizen. If not, then I must have been a citizen of Canada all these years and didn't know about it since my father was a Canadian citizen until I was about 5 years old. Andrew Jackson? Guess what. His parents were born in another country. Ditto even George Washington.