And then there’s the campaign of character assassination against Elizabeth Warren, the financial reformer now running for the Senate in Massachusetts. Not long ago a YouTube video of Ms. Warren making an eloquent, down-to-earth case for taxes on the rich went viral. Nothing about what she said was radical — it was no more than a modern riff on Oliver Wendell Holmes’s famous dictum that “Taxes are what we pay for civilized society.”

But listening to the reliable defenders of the wealthy, you’d think that Ms. Warren was the second coming of Leon Trotsky. George Will declared that she has a “collectivist agenda,” that she believes that “individualism is a chimera.” And Rush Limbaugh called her “a parasite who hates her host. Willing to destroy the host while she sucks the life out of it.”

What’s going on here? The answer, surely, is that Wall Street’s Masters of the Universe realize, deep down, how morally indefensible their position is. They’re not John Galt; they’re not even Steve Jobs. They’re people who got rich by peddling complex financial schemes that, far from delivering clear benefits to the American people, helped push us into a crisis whose aftereffects continue to blight the lives of tens of millions of their fellow citizens.

Yet they have paid no price. Their institutions were bailed out by taxpayers, with few strings attached. They continue to benefit from explicit and implicit federal guarantees — basically, they’re still in a game of heads they win, tails taxpayers lose. And they benefit from tax loopholes that in many cases have people with multimillion-dollar incomes paying lower rates than middle-class families.

This special treatment can’t bear close scrutiny — and therefore, as they see it, there must be no close scrutiny. Anyone who points out the obvious, no matter how calmly and moderately, must be demonized and driven from the stage. In fact, the more reasonable and moderate a critic sounds, the more urgently he or she must be demonized, hence the frantic sliming of Elizabeth Warren.

So who’s really being un-American here? Not the protesters, who are simply trying to get their voices heard. No, the real extremists here are America’s oligarchs, who want to suppress any criticism of the sources of their wealth.