The man was standing alone, leaning against the wall in the still half-empty conference room that the Marco Rubio campaign had rented for the senator's "big" Tampa rally. It was only 15 minutes before start time, and people were only trickling in. "Are you a Rubio supporter?" I asked the 60-something gentleman. "No. I'm just here to see the train wreck." While in line 30 minutes before the event waiting (with only a couple of hundred other people) for the door to open, I heard several say, not that they had come to support Rubio, but that they were now...