Sen. Marco Rubio (R-Fla.) said asking whether a politician has ever tried marijuana is a "worthless question" in American politics.Rubio, a potential 2016 candidate for president, has consistently dodged the question about if he experimented with the drug as a younger man. In an interview that aired Monday from ABC News-Yahoo News, Rubio reiterated that answering the question honestly is a lose-lose."Here is the problem with that question in American politics," he said. "If you say that you did, suddenly there are people out there saying it is not a big deal, look at all these successful people who did...