By now, most everyone who spends time online has seen the viral video of the confrontation between the mentally ill man and the younger black man: http://www.youtube.com/watch?v=lQJFv9SMSMQ
...prompting tens of thousands of opnions to be strewn into the ether, reminiscent of when the young woman threatened an elderly woman on Atlanta mass transit: http://www.youtube.com/watch?v=zXz-tlK2pkI
The vast majority of those opnions are in regards to the racial element of the incidents. Everyone wants to be on the correct moral side of an issue, and ascribing a simple racial angle to the situation allows them to do this.
However valid the point is that racism is integral to all that is wrong in our society, it keeps obscuring the deeper truth about mental illness. Mental illness often manifests itself as racism, at the point when it crosses the line from ignorance into irrationality; akin to the difference between an animal that bites because it's starving and an animal that bites because it has rabies. But when we think of mental ilness, we all too often think of it through the lens of morality: no matter how disordered a person's behavior, he or she "should have known better."
In this, we're no better than the wilfully-ignorant religious of centuries past, who viewed mental illness as God's punishment for sin, or as being posessed by the devil. And I also see very little progress since the time when men and ladies of quality would tour insane asylums so as to be amused by the "loonies."