Zombie facts were hardly created by the Internet; even a brief perusal of the partisan newspapers of the 19th century will make that plain. But today’s rumors have a self-perpetuating quality, which is accentuated by the erosion of trust in institutions that had once seemed authoritative. Gallup reported in September that Americans’ distrust of traditional media had hit a historic high, while approval of Congress had hit an election-year low. As more people turn to blogs for news and commentary, readership separates between conservative and liberal sites, with little cross-traffic. Self-proclaimed fact-checking sites proliferate, beholden to no particular standards. An editor of one of these sites contacted me about the Obama-Hitler essay, thinking he had reached the David Kaiser of the Naval War College. That did not inspire confidence.

The legal scholar Cass R. Sunstein recently wrote in these pages that efforts to forge common understanding on politically divisive issues might be most effective if we paid attention to the sources of information and not just how the information was presented. “Our initial convictions are more apt to be shaken if it’s not easy to dismiss the source as biased, confused, self-interested or simply mistaken.” Exactly — which is presumably why the authorship of the e-mail hoax was faked in the first place. About a month after the first one arrived, the e-mails showed a note had been added to the opening of the essay: “This is enlightening. Lest you think it was written by some right-wing kook, David Kaiser is a respected historian.”

As the great political theorist (and famous comedian) George Burns taught us, “if you can fake sincerity, then you’ve really got it made.” (Tellingly, versions of that quotation have been attributed to Groucho Marx, Jean Giraudoux and Daniel Schorr, among others.) Mr. Sunstein’s solution might work in a world in which identities were less easily faked, forged or stolen. After three and a half years of trying to debunk it, however, the Obama-Hitler essay still haunts the Internet (and my in-box).

And yet there is a bright side. After I began receiving the e-mails, I drafted a brief form letter to send in reply, pointing out the fake authorship. Whereas many correspondents had spewed incredibly hateful slogans in their initial messages, nearly all reverted to polite civility once the error had been pointed out.

One reader had been so inspired by the essay that he took my photograph from my Web site and posted it, along with my full résumé and the text of the essay, on his own — a conspiracy-addled “new world order” site that made the essay’s contents seem tame. When I finally reached him by phone to ask if he might take the posting down, he agreed, and I was surprised by how quickly our conversation turned to remarkably ordinary topics. There was no more howling about government plots or millennial apocalypse; the talking points faded away. We found we were but two people caught in a misunderstanding. Despite the rancor and factual recklessness of our latest election season, there might be hope for us yet.