Days later, media stories still made reference to the nonexistent whips supposedly wielded by the agents.

Advocacy groups simply willed the whip story to be true, and for a swath of America — basically anyone foolish enough to take what Harris and Biden say at face value — they have succeeded.

Despite the haze of misinformation, the fact-checkers didn’t descend en masse. No Twitter accounts were suspended. All the people who pride themselves on purportedly defending American democracy from falsehoods and propaganda spreading on social media (and there’s unquestionably a lot of it) stood aside or joined the pile-on.

Press outfits went out of their way to label falsehoods promulgated by President Trump as such. Indeed, they gave every indication that they relished doing it.

In contrast, the New York Times story about Biden castigating the agents didn’t suggest that he might be wrong. In fact, the original version of the article reinforced his smear by referring to “the images of agents on horseback chasing, and in some cases using the reins of their horses to strike at running migrants.” The paper had to run a correction.