I don't think there is a good one, I think it's time for a diagnosis. So, why would people spout such nonsense? Three reasons I can think of:
Groupism. Some people think the unit of justice should be the group rather than the individual. So, given that members of minorities in the past suffered a lot of injustice, to put it mildly, these wrongs can be righted if other members of these minorities alive today are given more than their fair share. Or rather, a more-than-average share is fair. The idea that people today should be rewarded for other people suffering in the past just because they share certain characteristics with them is so hard for me to even wrap my head around that I have considered I may be suffering from a lack of imagination and empathy. For the time being, though, I prefer the interpretation that it's the proponents of this view that have something to answer for.
The Outcome Fallacy. Assumption: If there were no racism, each group would, collectively, attain the same outcome as all the others. Observation: Colourblind policies do not lead to different groups attaining the same outcomes. Conclusion: Colourblind policies are racist. (Hint: the assumption may be wrong.)
Identity Politics. This is the biggie, I think. You're not much of a punk rock insider if you like the Ramones. Everyone likes the Ramones. If you're an expert concerning some Portugese band whose whole output consists of flexidiscs published with Greek fanzines in the late 1980s, then we're talking. Likewise, you're not much of an anti-racist if you're simply against racism. Even the conservatives are against racism these days. You'll have to offer a little more. The more extreme, the better.
Bonus moderator: Plain old self-interest. Flavour A: Person is member of minority group. Flavour B: Person is professional protector of minority group.
(Note: Is also applicable to other -isms.)
My, my, I'm starting to sound like an old curmudgeon on this blog. In real life, I am a sensitive and tender person! So let me finish by recommending Midnight in Paris, Woody Allen's latest, which is extremely charming. Even better, seen for the first time today, and also set in Paris: The 1956 Le ballon rouge. Most lovely. Most lovely indeed.