"Racism" against white people in the US is completely devoid of systemic material consequence. Understanding definitions isn't about "mobs" or even ideology, it's about identifying what happens in incidents of racial bias and why those things happen.
Fair enough, but does that make it "good" or simply "less bad"? And if it's just "less bad", then why should we tolerate it when there's no dichotomy between "racism against whites" and "racism against minorities" (i.e., we can and should aim for a world with no racism at all)? Further still, once you've established a racial worldview with a racial hierarchy that puts whites on the bottom, you've established a framework that facilitates white supremacist arguments (both by making it easier to frame whites as victims of racism and by validating racial worldviews in general--a worldview that puts whites on the bottom is a lot closer to a worldview that puts whites on the top than an egalitarian worldview is to either). Liberalism (i.e., treating people as individuals instead of identical constituents of their race) has been the driving force behind the massive reduction of white supremacy and anti-minority racism; it's an enormous success and an important bulwark that protects minorities. Why should we erode this important bulwark by replacing it with a system that (1) perpetuates injustice against whites and (2) paves the way for white supremacy? Racism is lose-lose.
