Reporting from Washington -- When President Obama says he has the best healthcare in the world, he isn't kidding. The White House medical unit, with a staff of four doctors plus nurses and physicians' assistants, is steps from his office. Treatment is free for Obama and his family (as well as for the vice president and his family). During the president's travels, a doctor and nurse ride in a limousine in his motorcade. An emergency medical technician comes too, with an ambulance. Air Force One is stocked with equipment for an on-board operating room. On overseas trips, two medical teams...