"If he hadn't inherited $200 million, you know where [Donald] Trump would be? Selling watches in Manhattan." It was Marco Rubio's big moment, the one that was supposed to damage the GOP front-runner. It wasn't a bad line. The zinger illuminated that Trump wasn't self-made. It made him seem like the avatar of New York's worst values--a street hustler from pre-Giuliani Times Square. Rubio's riposte got a laugh, but that was it. But he administered his blow too quickly, after a dizzying oppo dump of Trumpian facts--bankruptcies, lawsuits against Trump University, hiring illegal workers and so on. Like a hormonal...