Slowly and painfully — it’s somewhat exhausting to be honest. When I have a discussion with someone who expresses something in blatantly racist (or sexist) way I tend to find that they just have troubles with expression in general. Other times it is much more dire and they need to be challenged issue-by-issue again-and-again (sometimes on the same points). It is imperative that we attack bad ideas rather than bad people. Once an issue becomes personal it becomes harder to convince them of an error in their reasoning or logic. I’d advise people to keep calm and avoid accusatory language. It is the difference between addressing someone who claims blacks are criminals with, “You are a racist idiot!” versus “There are significant racial disparities in sentencing decisions in the United States.” Another important aspect is to teach children about race rather than expecting color-blindness since racism isn’t necessarily taught. If we remember that knowledge is the best tool to use against racism, sexism, and other unfair prejudices we may be able to overcome what Malcolm X described as the “incurable cancer” of America.