Anger has a peculiar power in democracies. Skillfully deployed before the right audience, it cuts straight to the heart of popular politics. It is attention-getting, drowning out the buzz of news cycles. It is inherently personal and thereby hard to refute with arguments of principle; it makes the political personal and the personal political. It feeds on raw emotions with a primal power: fear, pride, hate, humiliation. And it is contagious, investing the like-minded with a sense of holy cause.
Trump and other practitioners may reap short-term gains, but history suggests they will provoke a fearsome backlash.