Who is dismissing what now? Calling racism ignorance is labeling it, not dismissing it.
Can you elaborate on the bolded selection? I don't really see it as much more than a very limited number of vocal hate mongers leading a larger number of ignorant sheep around by their noses, honestly. Reminds me of a church, actually.
It is an implicit dismissal of the issue. By labeling the racist ignorant you have classified him and excused him. "Oh" the mind thinks "he's just
ignorant". He's not ignorant, he's possessed of a deeply held, and to him well justified belief that a certain segment of the population is evil by default. He can tell you why, and he knows the arguments against him. That's not mere ignorance.
That said, obviously racists are people too. Some will be more ignorant than others, more apt to follow the lead of another, or more apt to lead themselves, but again, to simply label the whole lot of them ignorant is to label racism as ignorance, and that is simply not the case.