If you don't get the joke:
Within the Harry Potter stories, there is a rather obvious Plot Device. Every DATDA Teacher that they get turns out to either want to murder Harry, or have some horrible secret that prevents them from staying on as a teacher.
The analogy made me embarrass myself at work with laughter.
H/T: InCali (Commenter on Hot Air) 4th down from the top on the 5th page...
French voters in the U.S. have no use for Le Pen
23 minutes ago