I don’t expect gay people to prove to me, a straight person, that there’s actually homophobia. I don’t expect poor people to prove to me, a Harvard grad, that hunger and poverty are widespread problems. And if someone asked me, as an Asian person, to “prove” to them that racism exists, I would laugh all the way back to Chinatown. Marginalized groups are not responsible for explaining their marginalization to you. If you are actually concerned, you would take the initiative to do some research yourself instead of showing up at some oppressed group’s door step demanding a list of citations for things (racism, sexism, etc.) that are proven time and time again in the real world.