When I, a white young boy, grew up in The South and saw the Klan, my father taught me to never do business with them, never enable their behavior, never let their organization rent rooms from venues I may own, and to decline all of their business even if they were paying extra to be your customer. For as long as he could remember, and his father before him, the Klan and other fringe organizations would always cry and…
I've never seen them IRL. I wonder how prevalent the Klan actually is.
The central problem is that people are lazy as hell. The answer to this problem and indeed, most problems we face in society, is building and maintaining stronger communities, and encouraging critical thought and an educated and participatory citizenry. But this is incredibly hard, and is incompatible with most forms of grift which people have set up to enrich themselves. In the end, however, this is really a description of all of human history. It will always be the case that building and maintaining a "good" society is incredibly hard work, which most people reflexively don't want to do (in the same way that most people don't want to do the dishes, or take the shopping cart back to the shopping cart corral at the grocery store).