The rule of thumb in any White House is that nobody is indispensable except the president,? said The New York Times, but Karen Hughes has come as close to that description as any recent presidential aide.? Karen Hughes has worked beside President George W. Bush since, as she says, the motorcade was only one car and he was sometimes the one driving it.? As counselor to the president, she brought the working mom?s perspective to the White House, often...