The comparisons between Adolf Hitler and Tom Riddle, who became the Dark Lord Voldemort, are hard to miss.
The anti-Semitic German dictator sought Aryan blood purity, just as Riddle seeks to rid the wizard world of “mudbloods,” or wizards who were born of two non-wizard "Muggle" parents.
It has been suggested, though never proven, that Hitler was part Jewish. Hitler himself was sufficiently concerned about the question, that according to Hitler historian John Toland, the Führer had the Nazi law defining Jewishness rewritten to exclude himself and Jesus Christ.
This directly compares to Riddle’s obsession over his own mixed ancestry. He was a "half-blood" whose mother was a witch and father was a Muggle.
Hitler used propaganda to control information to the German people. It is hard to miss Rowling’s disdain for the media in her villainous reporter, Rita Skeeter, whose Quick Quotes Quill fabricates stories based on the whim of the moment. Moreover, the wizard newspaper, The Daily Prophet, is repeatedly subverted by the bumbling Ministry of Magic, and, in the final book, it becomes the mouthpiece for Voldemort's own brand of ethnic cleansing.
And of course, the life and death fight against totalitarian forces underlies the entire series.
