Jimmy Carter's unemployed grandson has said he helped leak damaging video footage of Mitt Romney in retaliation for the Republican's habit of maligning his grandfather on the campaign trail. .......As the story exploded, Mr Carter emailed his 87-year-old grandfather to tell him he was behind the revelation that was rocking Mr Romney's campaign. The former president replied "James: This is extraordinary. Congratulations! Papa." The younger Mr Carter was only three when his grandfather was pushed out of the White House by Ronald Reagan in the 1980 election but said that he was still angered by Republicans who accused the former...