What does Brexit have in common with Donald Trump’s instantaneous denunciation of the FBI’s announcement that it found nothing criminal in Hillary Clinton’s handling of State Department emails? Two things: Both are rooted in the notion that, as the presumptive Republican nominee put it, “the system is rigged;” In both instances, that perception is part of a fundamental political realignment in which the old divisions between right and left are blurring into illegibility. We are only beginning to discern some of the implications of such a shift—and none so far are heartening. The continuing chaos that has followed Britain’s vote to bolt the ...