My opinion in this matter is very much controversial.
I do think Donald Sterling has earned a reputation of being a racist and I'm not a bit surprised, In fact I think it's shocking that he is the only billionaire born in the 30s who has been accused of such perception. He was raised in the separate but equal years, he grew up in a completely different time for racial relations but I also think he has made strives towards being more open minded.
Now here's where my opinion gets controversial. I don't think he was being racist in that phone call in fact I think he showed how insecure he really is. He forbade his trophy girlfriend to make public appearances and put pictures of her with other men (specifically black males) in her public profile. His reasoning although biased makes sense, he is an old man, he is being taken advantage of by his trophy girlfriend yet he doesn't want her to rub in his face that she is unfaithful, furthermore he doesn't want his friends to see him as the old fool she may be making he look like to his wealthy white friends of the same age group.
All in all I do think he deserves some punishment but we'd be lying to ourselves if we pretend people in their 80s are as open minded as we now are. They were raised in different times and as biased as their opinions are they are protected to have it.
I support his freedom of speech and I support the monetary punishment he may receive from the private industry however I think the NBA is out of line and trying to save face by banning him from the NBA and forcing him to sell his team. If they really had a problem with Sterling they'd have gotten rid of him long ago as this isn't the first time he had a racial fubar.