If you want to understand the Left, most of what you need to know can be summarized thus: The Left hates inequality, not evil.
As one raised as a New York Jew (who, moreover, attended an Ivy League university) and therefore liberal -- it took me a while to recognize this fatal moral characteristic of the Left. But the moment I realized it, it became immoral not to oppose leftist values.
It is neither possible nor virtuous to be devoid of hatred. Even those who think it is always wrong to hate must hate hatred. The question therefore is not whether one hates but what (or whom) one hates.
For example, on the basis of the value system that I hold -- the Judeo-Christian -- I try to confine my hating to evil. By evil I mean the deliberate infliction of unjust suffering on the undeserving; cruelty is the best example of such evil.
Those who hate evil hated the Soviet Union. The Soviet Union, after all, was a made-up country, created by a band of gangsters called Bolsheviks and Communists. They murdered between 20 million and 40 million innocent people, spread their totalitarianism around the world, and thereby rendered hundreds of millions of people slaves and automatons.
From the 1930s to the 1950s, liberals and social democrats vigorously opposed communism. But the rest of the world's Left, especially its intellectuals and artists, not only did not oppose communist governments, they were the greatest defenders of communism.
By the end of the Vietnam War (begun and prosecuted by liberals), however, most liberals abandoned anti-tyranny, anti-evil liberalism and joined the rest of the Left. Since the late 1960s, with almost very few exceptions (one is Sen. Joseph Lieberman), "liberal" and "Left" have become synonyms. (That is why The New York Times characterizes the Nation, a far-left journal, as "liberal.")
Thus, when President Ronald Reagan called the Soviet Union an "evil empire," the liberal world condemned him. The Cold War, once regarded as an epochal battle between freedom and tyranny, came to be regarded by liberals as an amoral battle between "two superpowers."
Likewise liberals almost universally mocked President George W. Bush when he labeled Saddam Hussein's Iraq, North Korea and Iran an "axis of evil." It takes a mind that either has little comprehension of evil or little desire to confront it to object to characterizing three of the worst regimes in modern history as "evil."