These are people who have arrived at a tacit agreement to claim they believe something they almost surely don't believe because it is so offensive to the people they hate.

Not to get too far off on a tangent, but it's the same for almost all Holocaust Deniers. They know it happened, but they get such enjoyment from torturing the people who know how serious it was (while wearing their Auschwitz t-shirts).

We need a better word than "Gaslighting".