< snip> After weeks of denigration of the Democratic challenger's Vietnam war record, Mr Kerry's backers have responded with allegations against the President - including the claim that he was once photographed in uniform wearing a medal ribbon he had not earned. As polls showed that Mr Bush had edged ahead of Mr Kerry for the first time, a pro-Kerry organisation labelled the President an "impostor" over the photograph, taken in 1970 and discovered in his father's Presidential Library in Houston, Texas. The ribbon is an Air Force Outstanding Unit Award - which was not awarded to the 111th Fighter...