@Judi: “Today the racial slurs about our president couldn’t go unanswered.”
If you were to answer the racial slurs, what is it that you feel would be improved?
If your friend had made a factually-incorrect statement, you could provide information to inform him/her. This would at least have the possibility of resolving the fact that your friend is ignorant about something (like we all are).
But if your friend just said something like “Obama is a n**ger!”, what information could you provide to counter that confusion? Nothing. So, in this case, what benefit could come from answering the comment, and what could you say?
I have a Facebook account that I use once or twice a year to post a few photos of the kids and communicate with some of my older relatives who forgot that there is something called email. But there are relatives that had friended me and then just posted some of the worst and most confused ideas I had ever heard coming from someone who wasn’t wearing a swastika. I just blocked most of them and unfriended the most egregious.
The thing is – it seems like you are feeling the pain of some jackass making a racial slur on Facebook. The corrective might be to just remove yourself from the equation by blocking or unfriending so that you are not exposed to this nonsense. You’ll likely feel better, and s/he has one less vicitim.