Speaker: Gore Vidal? Peter Bogdanovich? Sue Mengers? Jason Epstein? Anonymous? Subject: Truman Capote? Elvis Presley? Michael Jackson? Gore Vidal? Dear Quote Investigator: Pop star Michael Jackson died in 2009 when he was only fifty years old. One memorably caustic remark I heard at that time was: His death was a good career move. Apparently, the …