Good comment. Isn't that the entropic theory of meaning? 'Racist' is used up, out of energy, so let's move on to 'supremacist'.
The media routinely conflates any white oriented organizing with the idea of 'supremacy' thereby creating a pejorative image. It could also just be 'nationalist' as in Black Nationalist' but that is OK.
This is definitional hypertrophy and the media has engaged in inflating certain ideas since the sixties. 'Racist' used to mean Birmingham regs now it means 'even noticing race.' Sexism used to mean hiring only women for nurturing jobs,now it noticing a woman for her looks.
After they entropically use up 'supremacist' they will move on to 'pale' as long as it is only applied to 'male'