A single individual has no power to mitigate the situation. Even a minority group, like African-Americans has limited power to affect change. All we can do is try to survive the age we are living in and do our small part to change things for the better.
Of course I would be angered at this slow crawl if I were an African-American, but there are many areas of our society that are utterly and intolerably unfair. As a drug user I feel that we are unfairly persecuted, but I can't get angry at GWB or Barack Obama for not decriminalizing immediately. It would be politically impossible. I'm not equating the chosen lifestyle of a drug user with the unchosen attribute of skin color, but it should be helpful for you to understand the situation.
I am angered at the slow progress towards justice in this regard, but at the same time I undestand that there are reforms that our society is simply not ready to accept, no matter how fervent my beliefs.
I am not attempting to "explain" racism but I will defend the admittedly slow progress toward equality our country has made.