The Hill published this very interesting article about Marco Rubio. It notes:
Rubio seemingly ruled out being part of a presidential ticket next year when, during an appearance on “Meet the Press” in May, he told host David Gregory: “I won’t consider it. I don’t want to be the vice president of the United States.”
I hope Rubio will have a change of heart, and I predict he will. According to the betting markets, there's a 36% chance that not only will he agree to be the nominee he actually will be the nominee.