Taking a neutral stance is a tacit endorsement of the validity of the message being spread as being worthy of discussion. Holocaust denial does not deserve its day in the sun, even if the outcome were a thumping victory for reason and truth. Besides, the Holocaust deniers are not convinced by reason or argument. Their beliefs are impervious to facts, which is why debate is a pointless exercise except to give them a platform by which to spread their message, organize, and legitimize themselves in the marketplace of ideas.