The Down Low Support For Radical Groups.

When issues involving culture are discussed some people, especially those sympathetic to a particular ideology or social concept, raise pin headed lame allegations such as racism and/or bigotry.
The organizations themselves such as Radical Muslims, The KKK, or Farrakan's Nation Of Islam are relatively small in number but enjoy a much larger population of latent supporters. These supporters find it difficult to defend and/or debate the antics of the abovementioned groups, instead they accuse critics of social intolerance. This is a tactic to stifle criticism and debate regarding  the behavior of radical groups.
Human Nature, i.e., ethnocentrism probably accounts for various segments of  society supporting certain radical groups and in some cases ideology plays a significant role.