From that link: "It is important to push for the understanding that racism is 'prejudice plus power' and therefore people of color cannot be racist against whites in the United States. People of color can be prejudiced against whites but clearly do not have the power as a group to enforce that prejudice."

That's pretty much exactly the case! Thanks for the great quote.

That's racist nonsense. Racism is extrapolating a set of unfounded biases across an entire race, which is exactly what you're doing.

So Barack Obama couldn't be racist against a school janitor because the school janitor has more power?