They all know it's a blatant forgery, but the sad fact is that they persist in their insistence (when they are making a stab at explaining why) that all that boozhwa about Bush and the National Guard was certainly true because they WANTED it to be true so bad - and that it's perfectly understandable that a little bit of a gap had to be filled in with "recreations" of what must surely have existed at one time. . or, manufacture needed evidence in order to convict. Welcome to the convoluted world of liberals.
Remember Dan Rather saying that it didn't matter whether or not the documents were authentic -- Bush still needed to answer the questions they raised?