If you believe the AP today...Tiger is racist because A) he fails to identify himself as black and B) he only cheated with white women.

His mother was white, perhaps he has the thing about wanting to marry his mom, WHAT Oedipus's
Regardless, we do have this small little fault as humans that causes us to get out raged when a hero is brought down to our level.
Our hero's have to be better then us in all ways so we have something to strive for, some thing to be proud of.
This is one heck of an onus to place on anyone, we are taking their right to live a normal life and demanding they live up to a standard we can never do.
We need to think the best of our hero's, when our hero's crumble under the weight of being perfect to everyone, then we feel used and betrayed.
This angers us and we are all to willing to help them destroy themselves.
Tiger was a HERO to millions who for somehow identified with what they wanted to be. Now this man shows that he is less then his worshipers.
So the anger has turned to the desire to totally destroy the Hero and go looking for another person to fill the shoes of a false God.
I find it interesting as a Peon of the Realm to watch just how far a Hero can fall due to his own decisions.