From Stacy McCain:

The greatest “achievements” of the Left have historically been genocidal in nature, whether we are speaking of Stalin in Russia, Mao in China, Pol Pot in Cambodia or Mengistu in Ethiopia. Every left-wing radical leader as far back as the French Revolution has turned out to be a mass murderer, but we aren’t supposed to notice this trademark telos of radicalism. We are expected to think of these blood-soaked fanatics as idealists who, perhaps, got a little carried away with their idealism and thus killed millions of their countrymen. The fact that such “idealists” seizing power is always swiftly followed by the arrival of the Four Horsemen of the Apocalypse — just a coincidence. “Past performance is no guarantee of future results.”

Everything they do in following their star leaves the world worse than before.