Karl Rove, the former senior adviser to George W Bush, has cast serious doubt on Sarah Palin's viability as a White House candidate, questioning if the American people thought she had the "gravitas" for the "most demanding job in the world". Expressing the strongest public reservations about the conservative star made by any senior Republican figure, Mr Rove said it was unlikely that voters would regard someone starring in a reality show as presidential material. In two weeks, the former governor of Alaska launches a cable television series exploring her home state's wilderness. "With all due candour, appearing on your...