On p. 116 of my copy of Sister Outsider:
Somewhere, on the edge of consciousness, there is what I call a mythical norm, which each one of us within our hearts knows "that is not me."
In america, this norm is usually defined as white, thin, male, young, heterosexual, christian, and financially secure. It is with this mythical norm that the trappings of power reside within this society.
Those of us who stand outside that power often identify one way in which we are different, and we assume that to be the primary cause of all oppression, forgetting other distortions around difference, some of which we ourselves may be practicing.