Rubio never had a real job in his life. He's been in government.
Anyone who studies the human political animal, can easily see that he "lusts" for the Presidency. He WILL run in 2016 for President (or jockey for the VP position)
From what I have seen of Ted Cruz, he’s much more impressive than Rubio. Unfortunately the “natural born citizen” question is even more acute in his case because he was born in Canada (where his parents were temporarily living) and his father (a Cuban immigrant) did not get around to becoming a US citizen until many years after Ted was born.