I'm going to report my coworker's racist comment to HR
Has he done it before?
Yes, that happens all the time, and his boss just does nothing about it. He deserves a penalty for that, at least a warning.
Good idea.  It is the right thing to report racist behavior in a workplace.
He has a warning now.
That you for standing up for those with no voice. It really isn't right what they did. I am sorry HR is so powerless to remove them since they do this all the time.