Of the various memes purporting to demystify the Trump era, one that has proved resilient is invocation of the Roman republic’s decline as harbinger for the fraying of the United States today: Last year, Edward Watts published “Mortal Republic: How Rome Fell Into Tyranny.” He acknowledges that Rome’s fall “doesn’t prescribe what the future will be for us,” but embraces the idea that its decay “offers a chilling lesson to modern Americans.”

In March, a website called Fabius Maximus, after the famed leader of the republic in the 3rd century B.C., published a post headlined “America isn’t falling like the Roman Empire. It’s worse.” And last month, in a lengthy essay for New York magazine, Andrew Sullivan noted that our Founding Fathers were particularly concerned with Rome’s fall from republic to autocracy and set President Trump up as a would-be Caesar or Pompey — a charismatic, polarizing figure with bare regard for rule of law. Sullivan bemoaned the accelerated erosion of Republican and Democratic norms during Trump’s tenure and warned that “in America, the question of whether this history will repeat itself hangs ominously in the air.”

Not really. What hangs in the air, rather, is the willingness of too many to make those facile comparisons. Rome is, truly, ancient history.

The Trump’s-America-as-ancient-Rome formulation is a misuse of antiquity as a barometer for the future. Sullivan, for instance, acknowledged the distinctions between Rome then and America now but suggested there exists in the past certain templates that offer a preview of our present and future. He charted a Rome that once exalted the virtues of civic responsibility but, starting in the late 2nd century B.C., was racked by conflicts between populists appealing to the people and then by powerful elites who built their own factions and armies and were dedicated to maximizing their own power, a multi-decade process that culminated in the rise and eventual assassination of Julius Caesar.

The Roman lesson is appealing in part because America’s Founding Fathers were steeped in the literature of ancient Rome. In a letter late in his life to John Adams, Thomas Jefferson wrote, “I have been amusing myself latterly with reading the voluminous letters of Cicero. They certainly breathe the present effusions of an exalted patriot, while the parricide Caesar is left in odious contrast. … I ask myself what was that government which the virtues of Cicero were so zealous to restore, & the ambition of Caesar to subvert?” For the Founders, republican Rome was an endless reference point. Benjamin Franklin quipped that the Constitutional Convention had laid the foundations for a republic, “if you can keep it,” acutely aware that republics have a way of descending into autocracy, especially if they become rich and powerful, then bloated and corrupt. That notion is woven into American lore and is now seeing a resurgence, not only on the left, but also on the right: Supreme Court Justice Neil M. Gorsuch, a recent Trump appointee, just published a book titled “A Republic, If You Can Keep It.”

But just because our Founders worried that the path of Rome might lie in America’s future doesn’t mean the analogy holds. As classicist Mary Beard explained in her book “SPQR: A History of Ancient Rome,” much of the traditional history of republican Rome, as written by ancients, is itself highly questionable in terms of historical veracity. They themselves were often partisans of a certain vision of the Republic and of certain factions in its later days, not to mention stylists concerned about the verve of their narratives. Much as you would not want to rely on a vision of the present as generated by the bestseller list, these sources — vital though they are — have their own issues. Using them as touchstones reinforces what is sometimes whispered in the academy, that history doesn’t repeat itself, but historians do repeat one another.

The then-and-now juxtaposition obscures more than it illuminates. As Sullivan noted, the levels of violence and discord in Rome dwarf anything that might be acceptable today. In one episode, in 133 B.C., Tiberius Gracchus, one of the early populists of the republic, and hundreds of his followers were killed by a mob, led by members of the Roman Senate. In another, the military commander Sulla assumed the title and powers of “dictator” in 82 B.C. and killed thousands to consolidate his authority.

The we-are-Rome cohort recognizes that the United States today does not have factions with their own armies (rogue militia groups notwithstanding) nor camps beholden to one leader willing and able to violently eliminate fellow citizens, but they still feel, as Sullivan put it, that “it’s impossible to review the demise of the Roman republic and not be struck by the parallel dynamics in America in 2019.” Actually, it’s quite possible; Charlottesville was violent and extreme and tragic by today’s standards. One person died.

Yet, for the we-are-Rome cohort, the lines blur: the Trumpian erosion of norms; the yawning gap between the few immensely wealthy and the rest; the gerrymandered trampling of democracy; the venality of elected officials in Washington; all add up to Rome redux.

One of the most pungent rebuttals of that view comes from Beard. In Britain, she is something of a left-wing firebrand, but she cautions against simplistic comparisons. She thinks the issue of citizenship (read: immigration) in the later Roman republic offers intriguing lessons for America’s present immigration debate, but overall, she resists easy parallels. Though it’s tempting to see Trump as a Julius Caesar (who both ended Rome’s republic and, via his assassination, ushered in the Roman Empire), she averred: “I don’t think Rome has got any direct lesson, I’m happy to say, for the United States. And we shouldn’t be too certain what kind of crisis we’re in, or even if we’re in a crisis.” Beard embraces the role of historian as a forensic analyst of known outcomes. That is impossible in the present. “If we knew how to analyze what we were going through, at the time we were going through it, we wouldn’t need historians.”

As scholars Ernest May and Richard Neustadt warned years ago in “Thinking in Time: The Uses of History for Decision-Makers,” the past is a dangerous temptation for analysts and commentators, and if you think you’ve found a golden analogy for the present, you’re almost certainly wrong and will almost certainly choose policies that make matters worse. History should be used, they said, to inform processes, not decisions. During the Cuban missile crisis, when President John F. Kennedy and his team recalled the events that led to World War I, they did not treat 1914 as an exact parallel but instead used it to remind themselves that bad decisions made precipitously can have disastrous and irreversible consequences.

Certainly, excavating the history of the Roman republic can help us understand the multiple pathways the present offers, but not with any clairvoyance about specific outcomes. Some of the challenges of that age are recurring human ones: how to balance individual freedoms with collective needs, determining what the rights and responsibilities of citizens are and what powers government should have. That’s a far cry, however, from using ancient Rome as a road map, template or crystal ball for identifying latter-day Ciceros and Caesars. It can be comforting to choose false certainty over real uncertainty, even if it says we are on a road to ruin. But whatever our apprehensions, our republic’s next chapter remains to be written; ancient Rome’s conclusion lies in the past.