Is there anything to implode? He's been hovering at roughly the same position for months, his campaign lacks any kind of central message, and despite the fact that the pundits love talking about him as the Republican Obama because he's young and a minority, he's a terrible speaker with no presence.
Actually I think Rubio is a very good speaker. It's just that he's content challenged, and tends to repeat the same cliches, and his own life story, over, and over, and over again. He needs to expand his repertoire.