The concept of race that was favored back in the old days is nonsense, but it is very, very hard to deny biological differences(apart from pigment) do exist. I mean, check out your a sickle-cell anemia support group. There probably are some, and I guarantee you, you won't find many Swedes there.
Or perhaps consider why people coming from a small, but very much maligned group (.2% of world population, I believe) net ~25% of all Nobel prizes. There's a million other examples.
Though, I suppose it is in the interests of harmony to stick one's head in the sand and pretend, there really are no differences. It's all just cosmetics.
Also, it's been found in a study that we have a biological 'tendency' for racism.
If someone does something bad to us, we more easily forget about it if the culprit belonged to the same group. If he is clearly different in some way, it takes longer to forget.