For a prime example of racism toward one’s own race, look at the interactions between Chinese, Japanese and Koreans during WW II: all three are eastern Asian race; yet they passionately expressed violent racism amongst themselves toward one another.
By the same token, it’s not right to segregate, neither is it right to promote based on “race”, gender, or any other artificial quota standards in business, schools, etc. MERIT should be the only criterion for promotion.
Ideologies, however, present another problem; some cannot and will not accept or tolerate others and can’t be mixed without promoting violence. Neither will some learn to tolerate others.