Joe Biden’s tendency to commit verbal gaffes is well known around Washington — and becoming better known around the country. In a television interview this week, Biden was making a point about presidential leadership when he mangled his history. “When the stock market crashed, Franklin Roosevelt got on the television and didn’t just talk about the princes of greed,” Biden said. “He said, ‘Look, here’s what happened.’” A couple of problems. First, television was in its infancy in 1929, and not many Americans owned a set. Second, Herbert Hoover was president. Roosevelt wouldn’t take office until March 1933. Other than that, we take Sen. Biden’s point about the need for visible presidential leadership.