For a while the media has assumed that this kind of identity-based politics inevitably favors the left, because 21st-century America is getting less white every day.

But that’s too simplistic, in part because the definitions of “white” and “minority” are historically elastic. If a “white party” seems sufficiently clueless and reactionary, it will lose ground to a multicultural coalition. But as African-Americans know from bitter experience, “whiteness” has sustained itself by the inclusion of immigrants as well as by the exclusion and oppression of blacks. That history suggests that a “multicultural party” may always be at risk of being redefined as a grievance-based “party of minorities” that many minorities would prefer to leave behind. (And leadership matters, too: A protean figure like Barack Obama can put together a genuine rainbow coalition, but it’s not clear how many other politicians can do the same.)

The key point here, though, is that whichever coalition is ascendant in this scenario, a politics divided primarily by identity is likely to be more poisonous than one in which both parties are offering more-color-blind appeals…

As John McWhorter wrote in Time magazine, by the time the grand jury handed down its non-indictment the original narrative about Ferguson could only survive with “a degree of elision” and “adjustment.” Which meant, predictably, that the potential for consensus receded, and how people felt about the story became primarily a matter of identification instead.