What do Joe Biden, Civil War General Winfield Hancock, Japanese assembly plants, malicious computer programs, Syrian refugees, and just about every U.S. president in the past several decades have in common?

Ding ding ding: They've all been called Trojan Horses.

The Democratic nominee for president is "a Trojan horse for socialism," President Trump alleged during a campaign stop in Oshkosh, Wisconsin, on August 17. In his presidential nomination acceptance speech later at the White House during the Republican convention, Trump repeated the claim verbatim.

Admittedly, these horses have become a little less literal since Odysseus came up with the idea of hiding his troops in a giant wooden ungulate, gifting the structure to the impenetrable Troy, only for the Greek army to emerge at night within the city's walls and slaughter their unsuspecting enemies. Listening to the Trump campaign's uncharacteristically consistent messaging this summer, it's clear that they've come to rely on the Trojan Horse political cliché as a crutch for slamming their opponent as being somehow nefarious and ill-intentioned, but without having to actually supply any explanation of how. As with the original, it all makes for a good story — though it reveals more about the accusers' desperate position than whoever's being called a metaphorical horse.

Politicians and pundits have been slinging the Trojan Horse accusation at their enemies for literally centuries; a recent investigation into the metaphor's resiliency by The Wall Street Journal found that the Elizabethans were using the term as threatening shorthand as long ago as 1559. Harper's Weekly political cartoonist A. B. Frost, though, might be the primary influence behind the Trojan Horse's use against political opponents specifically; ahead of the 1880 presidential election, he appended the head of the Civil War hero and Democratic candidate General Winfield Hancock onto a wooden horse, thereby suggesting "an empty political vessel who will allow the deceitful Democratic Party to take over the American government."

Whether or not the smear accounted in any small way for Hancock's eventual defeat by Republican James A. Garfield, the characterization of a politician as a mendacious "Trojan Horse" stuck: Franklin D. Roosevelt's New Deal got the cartoon version of Trojan Horse treatment, while Bill Clinton, Barack Obama, Mitt Romney, and Donald Trump have all been given the label in the past few decades. Democratic nominee George McGovern's campaign even adopted the term favorably, seemingly one of the few to understand that Odysseus was, after all, the cunning victor in that particular parable.

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Trump has been a fan of the Trojan Horse metaphor for years, having used the term on the 2016 campaign trail in particular to stoke Islamophobia against Syrian refugees. "This could be like a Trojan horse," Trump — no fine scholar of history or the Classics — ranted. "I mean, this could be a Trojan horse in a sense: 200,000 people coming into the United States, and let's say a lot of them would be ISIS."

But the heavy use of the metaphor this summer by his campaign has reflected an obviously intentional effort against his opponent. Vice President Mike Pence leveled the charge in his own RNC speech ("Joe Biden would be nothing more than a Trojan horse for the radical left"), then again on Wednesday while speaking in northeast Pennsylvania. Rudy Giuliani, never one to miss out on the fun, called Biden a Trojan Horse for "his party's entire left wing."

The Trump campaign has struggled to land blows on Biden, who fails to be the socialist boogeyman they'd clearly rather be running against. So, since painting Biden himself as a far leftist doesn't convince anyone, NBC News writes, "the president and his allies have settled on a different strategy: Paint Biden as an empty vessel for socialist radicals to exploit."

The Trojan Horse title, then, isn't so much a clever metaphor by Team Trump as it is a desperate placeholder: Biden is bad, the campaign wants to communicate, even if he doesn't actually hold the views they claim "will fundamentally change this nation." Does Biden want to defund the police? Does he want to abolish fracking, or eliminate borders? No, and the idea is sort of ridiculous, especially to those on the left: "I wish Biden was a real radical, because huge problems like COVID-19, global warming, and galloping inequality require huge solutions," writes The Week's Ryan Cooper. "Unfortunately, he is not." The socialist Trojan Horse threat, when added to a whole raft of lies about Biden's positions, serves the rhetorical trick of not having to adhere to reality or evidence by assuring supporters there's some yet-to-be-revealed extremity surely coming — just you wait.

Of course, there's a whole other possibility too: that Trump actually believes all this. To perceive the world as being stampeded by Trojan Horses, as he sometimes seems to, reveals a deep mistrust and paranoia of its mechanics. While there's a certain amount of theater and strategy behind labeling an opponent a Trojan Horse, particularly when you're lacking in good political dirt, Trump's suspicion seems to be bigger than mere literary metaphor. His belief in a Trojan Horse instead dovetails with his perception that there are "people that are in the dark shadows" conspiring with his enemy against him, and where every 77-year-old establishment Democrat harbors within him the possibility of bloodthirsty Greeks.

The story of the Trojan Horse is ultimately a lesson in heeding warnings, although Trump makes a less-than-convincing Cassandra if we extend the metaphor that far. Instead, all his crying "horse" only reveals how much his campaign is grasping to find a convincing threat in Biden, even this late in the election season. Perhaps they should work on tweaking the metaphor; after all, at least "a wolf in sheep's clothing" is still a wolf underneath. All it takes is a little pulping for a Trojan Horse to turn out to be paper tiger.