Unironically, Americans think like this because they're more progressive than Europeans (some, anyway; some are way less). Europe has a history of disenfranchisement too, and to the extent they don't see it much it's because they have more homogeneous societies (until recently, with refugees). The melting pot of the new world was always life on higher difficulty: you don't get to be racist while pretending you're not because you're never tested on it as a society. You don't get to outlaw slavery, posturing like you're doing it because you're just that virtuous when in reality it's because it's easy to do when your economy doesn't rely on slavery so it's an easy way to look good. In this crucible, minds are traumatized into reverse-racism and performative bullshit.