When Bill Clinton and George W. Bush announced a project jointly sponsored by their presidential libraries, news coverage focused on the style, not the substance, of the event.The Wall Street Journal said the two ex-presidents "could have been mistaken for a comedy routine." The Associated Press said they "shared laughs and a buddy-like banter."But behind the banter was a serious message. Their libraries -- along with those devoted to Lyndon Johnson and George Bush 41 -- are starting a leadership training program that is more needed than ever.