It is never directly spelled out but certainly heavily implied:
Tony Lip: "Hey Doc, we're both marginalized - me because I am not highly educated and you because you're discriminated against and have to fear for your life just because of the colour of your skin. EMPATHY! Oh, and I am not racist because I have a black friend."
Tony Lip: "Hey Doc, we're both marginalized - me because I am not highly educated and you because you're discriminated against and have to fear for your life just because of the colour of your skin. EMPATHY! Oh, and I am not racist because I have a black friend."