Today, the most recognisable, feted, popular man on Planet Earth will bestride the White House like a colossus. He'll pose for some photos in the Oval Office and probably crack a lame joke that leaves America's toughest political journalists guffawing sycophantic gales of fake laughter. When he departs, President Obama will shake his hand and feel very grateful that he was able to bask, albeit briefly, in the reflected glow of his guest's beloved VIP wattage. Tonight, the same celebrity icon will take his beautiful, equally famous wife to a basketball game in Brooklyn; the public will go crazy, while...