Depends on your definition of racism. And also, I am specifically talking about racism in the United States. And yeah, racism derives from white people attitudes that the whole culture then considers to be true. Why are black people always treated as the lowest social class? Because that's how it's been in history for a very long time. I don't think it's necessarily saying that black people can't be racist, but that there's a distinction of power that absolutely cannot be ignored. Even all of your examples of racism from non white people ignores a couple of things. Racism derives from the social hierarchy in society, and everyone sees it to their advantage to see black people below them. It has been speculated that race structure was specifically set up to give white people hundreds of years ago a sense of superiority over others. I'm not saying people can't be personally prejudiced, however I think this isn't a simple at all. These people call for the idea of power to be added to the idea, and the historical context of racism. Which has always been to group people into racial categories, and treat white as the top category. Does this mean black people can't have racist attitudes? Yes they can, however this ignores a lot of the power dynamics and many think this not sufficient.