As for the article, I don't think there is a right or wrong way to take it, and probably, looking at it from both perspectives makes the most sense.
I like Token's changing of the question to "why". And I think it's good to answer it from both perspectives. As a nation, why would I suspect violence if the group were black? Well, the answer, honestly, would have a lot to do with experience and history. To me, I would ask myself if that's fair for me to anticipate something based on other historical situations that are not entirely related to the current "gathering".
However, it does seem strange to me that the author doesn't also make the obvious connection to history and experience to answer the question of "why" a lot of America would anticipate a certain outcome. The fact that he doesn't look at history or make that connection, to me at least, does indirectly and passively imply that the answer is simply racism, and nothing more.
And that is something I take great offense to. In the same way that I'm not allowed to dislike Obama without being racist (I dislike his white HALF just as much as his black HALF).
Anyway, I don't think it's a bad idea for us to examine not only why we might react a certain way, but then move ourselves to asking if it's right. BUT, I also think it's a good idea for the writer to open his eyes and see that there are, in fact, real, NON RACIST, reasons all over our society that help explain why violence might be an expectation of a large gathering of black protesters.
Both perspectives are fair, and both should be exorcised.