I don't post much on here. This is one of the more interesting (and civil) threads I've seen on race in a long time.
@MarketStEl: Agree wholeheartedly regarding that trope. I always hated seeing it on t-shirts and in visual media because I thought it always ended necessary conversations before they could begin. Even if there was a historical reason for its beginning, it tended to linger in unhelpful ways.
I consider myself academic Left, and perhaps as such, I've always seen "prejudice plus power" as a helpful definition for racism. The reason I say this is because bias/prejudice is at the root of racism, but the power/threat of consequences is what gives racism its bite. I do agree with you that if one wants to avoid the potential problem of poor treatment from the black residents of a neighborhood, they shouldn't move there. That said, it's a terrible excuse. We have to examine the endgame here. What is the ultimate positive thing that we're trying to accomplish? It's a real cop-out to say, "hey, white person: if you don't want to experience the possibility of racism, don't move to a black neighborhood," for the same reason it's a cop-out to reverse the races in this instance. (And the same goes for any other racial/ethnic groups we may want to throw in: Asian, Hispanic/Latino, Indian or Deshi, etc.)
The reason I see "prejudice plus power" as useful is the same reason I've always hated the term "reverse discrimination." I know why and how that term exists, especially because there are some white people out there that use/have used it as a rallying cry. The two main reasons I've hated that term are 1) it implies that black people can't be racist (which is part of said white people's rallying cry) and 2) it removes the agency/power dynamic of said prejudicial person. We shouldn't shy away from a prejudicial person if they are embracing tactics of bias, no matter the race of said person. Prejudicial frames of reference can be smaller than we want to acknowledge.
The term "reverse discrimination" should be abhorrent to everyone because it implies that there is a tacit normalcy that exists in discrimination of white people toward black people, and the same tacit normalcy of black people enduring it from white people (and, of course, this still leaves other groups out of the equation).
All of this said, I don't mean to imply that we live in a post-racial dreamland, a picture that some in the greater media have occasionally painted. Racial issues are messier than before, if for no other reason than the fact that we can actually discuss them civilly these days.