Why is racism considered congruent to ignorance?

Racism is in fact not ignorance or stupidity at all, it is merely a manifestation of hatred and anger. (of course theoretically racism cannot exist there being no races from a DNA standpoint however the ideology is certainly extant.) Racism is a tool it unites nations (though rarely with a positive end result) - think Germany and now North Korea and China. Simply, my argument is this: racism cannot be ignorance because the "truth" that all men are created equal is arbitrary and relatively dependant upon the society, therefore racism as we know it is merely a manifestation of sociological cirstance and not ignorance or stolid intellect - both of which are incorrect connotations. If you have an opposing view or just a thoughtful opinion please divulge.