Institutional racism is real and because of that it can't be undone by just pretending everyone is equal all of the sudden. It is much more nuanced than you make it out to be.
That being said, many of the people that twitter banned are just straight up racist and xenophoic/intolerant speech should not be protected.
Any evidence of this claim? Cause as an outsider to the US I see a black president and a lot of reversed-racism (affirmite action I think you ppl call it)
For example, http://money.cnn.com/2015/08/06/news/ferguson-arrest-warrant... shows that people in Ferguson are being arrested for things that wouldn't even be considered a crime where I live.
Compare that with https://en.m.wikipedia.org/wiki/Ethan_Couch or http://www.cnn.com/2016/10/27/us/oregon-standoff-ammon-bundy... and you will begin to see how crimes committed by white people are often punished by a slap on the wrist when the same crime committed by a person of color would land them in jail.