Doug Brinkley is a big wuss Democrat....that I know for SURE!!
You may be thinking of Stephen Ambrose, who has been accused of plagiarism. I haven't heard Brinkley being accused of that--just of being biased towards Kerry in his latest biography. I'm disappointed in him, as he wrote some decent biographies before this. His take on the Cold War was always somewhat liberal, though, come to think of it.