Every age has its officious moralizers, people who try to assert their superiority by embracing the prevailing orthodoxy—whatever it happens to be—with exaggerated zeal. They want to feel righteous. So they hunt for transgressors at whom they can point an accusatory finger.
In the post-Christian West, the holier-than-thou types enforce the codes of political correctness. The proverbial witch whom these p-c Puritans long to prosecute is the white racist, who (in their minds) lurks around every corner. And since they believe the act of accusing others bestows virtue on the accuser, they cry “racism!” whenever they find a pretext for doing so.
They recently worked themselves into a lather of self-righteous indignation when they found out that the University of Regina cheer team, which happened to be all white, dressed up as cowboys and Indians for a costume party.