How is it that liberals such as Jeffrey Goldberg of Bloomberg View can identify racism when Republican presidential candidates mention the words “food stamps” or “poor neighborhoods”? Andrew Ferguson examines the phenomenon in his latest Commentary “Press Man” column (not yet posted online).

It’s an odd sort of racism that Goldberg has sniffed out. It uses no racial epithets, it has no apparent racial intent, it comes packaged in pleas for economic progress, and it bears no suggestion that their genes or melanin count make African Americans different from other Americans. What are we to make of a duck that doesn’t look like a duck, walk like a duck, or quack like a duck? Goldberg’s answer is to call it a duck, dammit. He and his ideological fellows have invented an ingenious tool for divining the kind of racism that shows no signs of racism. They call it the “dog whistle.”

It’s one of the “darkest political arts,” Goldberg explains: “the use of coded, ambiguous language to appeal to the prejudices of certain subsets of voters.” Here’s how it works. When Newt Gingrich mentions food stamps, he sends a signal to racists—toot, toot!—telling them that he dislikes black people as much as they do. The signal is received even though, as many observers have pointed out, white food-stamp recipients outnumber their black counterparts by a good stretch. The pitch is so rarefied that only white racists and liberal Democrats can hear it. When somebody says “food stamps,” both Jeffrey Goldberg and David Duke immediately think of black people. Don’t ask me why. …

… You could draw several conclusions here. You could conclude, for example, that liberalism has descended from a political philosophy into an empty assertion of moral superiority, a pose of indignation struck toward the people who dare to disagree with liberals. Vanity and untethered arrogance would account for why Jeffrey Goldberg can find evidence of racism among his political opponents even where it doesn’t exist.