Wildly Parenthetical blog presents some extracts from a forthcoming paper which among other things addresses the meaning of “race” in Foucault’s work (presumably Society Must be Defended).
Foucault positions racism as a technique for fragmenting the population into superrace and subrace, and thus as not simply attaching to what we might otherwise, in more everyday use, call ‘race’ but I think to a range of other ‘attributes’ including homosexuality and disability
Foucault’s use of the word race in his lectures and HoS is certainly worth looking into as it is not the usual one. I don’t recall use of the terms superrace and subrace in his work, although they are perhaps suggested. I sometimes think it would be better if he had said “blood” or heritage because the word race can be used as a foundation for all sorts of interpretations.