Racism  (Wikipedia) - Racism is discrimination and prejudice towards people based on their race or ethnicity.

Prejudice towards people based on their race or ethnicity is wrong, & is A problem, but not the only problem, in this country & the world. No question on that point, but the real question is how does one reduce it. 

In fact the term "white supremacy" is racist, in your ref.,per definition. That is judging a entire group of people by the actions of a few, so as to marginalize groups of people, & diminish the individual.

Maybe looking at the factors that make successful & productive citizens would be more helpful, then parading "racism", "white supremacy", etc., such as stable families, with married parents, & being married before having children.

https://www.city-journal.org/html/marriage-matters-15362.html