I voted for firing. Whitlock is a writer that has made his career discussing racial injustice and stereotypes and then makes a very poor joke about it. When he is called on it and asked to apologize he comes up with perhaps the worst apology I have ever seen.
Its wasn't an apology! It was just an explanation!
Saying "Here is how and why I was a tool" is not expressing any kind of regret for your tooly-ness.
This, to me, is even more upsetting than the tweet itself. We've all said or written things that we wish we hadn't, and most of us have the decency to recognize and genuinely regret it.
Whitlock is just being defensive when he should be contrite. I'm a big believer in forgiveness, but it needs to be asked for in sincerity.
If he was my employee, I'd fire him.