I mentioned the idea of differentiating between “prejudice” and “racism,” where racism = prejudice + power.

I really, really dislike this redefinition of the word "racism" and have ever since I first heard it (late 1980s? Early 1990s?) As far as I can tell it was coined by people to make it so that only people who are conventionally-labeled "white" can be racist. Which is, to be polite, utter bullshit.