I think one could believe the way you said and not consciously subscribe to a white supremacy hierarchy…but just by operating with a racist frame they would treat Black Americans in an inferior way. The person w/ anti-Black American behaviors would fuel maltreatment from others who observe & learn from their modeled behavior. Those observers may indeed carry a conscious belief in racial hierarchy. The point is anti-Black American sentiment is contagious and has ripple effects…including perpetuating white supremacy and anti-Blackness.