Not a precise analogy: Rubio was hardly an "unknown." He was the Speaker of the House, IIRC. He had campaigned, got elected, persuaded other elected legislators, he demonstrated the necessary skill sets.
Rubio’s analogy was not precise, but still somewhat applicable: and where it was applicable is that he did something that was “impossible” according to conventional wisdom and it was something that could probably have never happened before the tea party movement evolved aided by the continued growth of talk radio and Face Book and the internet sites and so on.