Do We Talk About Racism Differently Than Sexism?

Julian Sanchez thinks so:

We can point out sexist remarks or attitudes without getting derailed by pointless discussion of whether a particular person “is a sexist.” It even sounds a bit weird to pose the question as though it were a simple matter of “yes” or “no,” with the world neatly divided into sexists and non-sexists. Rather, we all get that, the culture being what it is, basically decent peopleand occasionally even level-seven gender studies Jediwill have imbibed unexamined sexist presuppositions or adopted mistaken empirical beliefs about gender differences. 

This is, presumably, because for all that our society may have historically denied women full equality, even at its worst it stopped short of denying their humanity. “Racism” is associated, in its practical consequences, with a system of violence and repression so irredeemably evil that we want to think of it not as a species of error, but as something so monstrously “other” that it creates a chasm between those contaminated by it and those free of its influence.

Thoreau agrees but examines the downside to removing "the 'nuclear' aspect from the word 'racist.'”