Five days on, the commentariat continues to drop anvils on Tom Perkins, who may have written the most-read letter to the editor in the history of The Wall Street Journal. The irony is that the vituperation is making our friend's point about liberal intolerance—maybe better than he did.

"I perceive a rising tide of hatred of the successful one percent," wrote the legendary venture capitalist and a founder of Kleiner Perkins Caufield & Byers. Mr. Perkins called it "a very dangerous drift in our American thinking. Kristallnacht was unthinkable in 1930; is its descendant 'progressive' radicalism unthinkable now?"

That comparison was unfortunate, albeit provocative. It's not always easy to be subtle in 186 words, as Mr. Perkins learned, though a useful rule of thumb is not to liken anything to Nazi Germany unless it happens to be the Stalinist Soviet Union. Amid the ongoing media furor and an ungallant rebuke from Kleiner Perkins, Mr. Perkins has apologized for the comparison, without repudiating his larger argument.

While claiming to be outraged at the Nazi reference, the critics seem more incensed that Mr. Perkins dared to question the politics of economic class warfare. The boys at Bloomberg View—we read them since no one else does—devoted an entire editorial to inequality and Mr. Perkins's "unhinged Nazi rant." Others denounced him for defending his former wife Danielle Steel, and even for owning too many Rolex watches.

Maybe the critics are afraid that Mr. Perkins is onto something about the left's political method. Consider the recent record of liberals in power. They're the ones obsessed with the Koch brothers and other billionaires contributing to conservative causes, siccing journalists to trash them and federal agencies to shut them down.