a lot of replies to this are pretty retarded but i also have a problem with the "power" definition of racism, actually two. the first is, at what scale? black people in america 50 years ago probably didn't have that much institutional leverage to push their agenda but within social groups or whatever you could definitely have a majority of racist black people oppressing white people. so my point there is that the power game is really dynamic and operating at many scales simultaneously so even if the general trend is benefiting white people more that doesn't mean power isn't being used to exact racism against whites in other contexts.
my other problem is i feel like power is something that's been shoehorned into this particular definition of racism when really it has nothing to do with the essence of racism. i'd be a lot more comfortable with a study of "racism and power" instead of people trying to do a hostile takeover on the definition of racism itself to exclude anyone but the most powerful group at a given place and time from having the ability to be racist, because i think the latter strategy takes the word away from the larger discussion. like ok you're saying it's not racist, but it's something, what do you want to call it? to me the power aspect of it is just a signal booster on racism, and again doesn't have anything to do with what racism actually is.