The U.S. Constitution owes a huge debt to ancient Rome. The Founding Fathers were well-versed in Greek and Roman History. Leaders like Thomas Jefferson and James Madison read the historian Polybius, who laid out one of the clearest descriptions of the Roman Republic’s constitution, where representatives of various factions and social classes checked the power of the elites and the power of the mob. It’s not surprising that in the United States’ nascent years, comparisons to ancient Rome were common. And to this day, Rome, whose 482-year-long Republic, bookended by several hundred years of monarchy and 1,500 years of imperial rule, is still the longest the world has seen.

Aspects of our modern politics reminded University of California San Diego historian Edward Watts of the last century of the Roman Republic, roughly 130 B.C. to 27 B.C. That’s why he took a fresh look at the period in his new book Mortal Republic: How Rome Fell Into Tyranny. Watts chronicles the ways the republic, with a population once devoted to national service and personal honor, was torn to shreds by growing wealth inequality, partisan gridlock, political violence and pandering politicians, and argues that the people of Rome chose to let their democracy die by not protecting their political institutions, eventually turning to the perceived stability of an emperor instead of facing the continued violence of an unstable and degraded republic. Political messaging during the 2018 midterm elections hinged on many of these exact topics.

Though he does not directly compare and contrast Rome with the United States, Watts says that what took place in Rome is a lesson for all modern republics. “Above all else, the Roman Republic teaches the citizens of its modern descendants the incredible dangers that come along with condoning political obstruction and courting political violence,” he writes. “Roman history could not more clearly show that, when citizens look away as their leaders engage in these corrosive behaviors, their republic is in mortal danger.”

Mortal Republic: How Rome Fell into Tyranny In Mortal Republic, prize-winning historian Edward J. Watts offers a new history of the fall of the Roman Republic that explains why Rome exchanged freedom for autocracy. Buy

Historians are cautious when trying to apply lessons from one unique culture to another, and the differences between the modern United States and Rome are immense. Rome was an Iron-Age city-state with a government-sponsored religion that at times made decisions by looking at the entrails of sheep. Romans had a rigid class system, relied on slave labor and had a tolerance for everyday violence that is genuinely horrifying. Then again, other aspects of the Roman Republic feel rather familiar.

The Roman people’s strong sense of patriotism was unique in the Mediterranean world. Like the United States after World War II, Rome, after winning the Second Punic War in 201 B.C. (the one with Hannibal and the elephants), became the world’s hegemon, which lead to a massive increase in their military spending, a baby boom, and gave rise to a class of super-wealthy elites that were able to use their money to influence politics and push their own agendas. Those similarities make comparisons worthwhile, even if the togas, gladiator battles and appetite for dormice seem completely foreign.

Cullen Murphy, whose 2005 book Are We Rome? makes a more head-on comparison between the fall of the Roman Empire and the U.S., argues that the changes in politics and society in Rome stemmed from one source: its growing complexity. Rome, during the Republic and Empire, had increasing and evolving responsibilities around the Mediterranean which its government constantly struggled to manage. Those challenges forced changes throughout the economy and society, sometimes for the better and sometimes for the worse. In general terms, he sees many of the same struggles in recent U.S. history.

“I think the U.S. is experiencing this same situation—we’ve never quite recovered from our victory in World War II, which left us with the world on our shoulders; and the implications of that responsibility have skewed things in every part of our society and economy, and put our old political (and other) structures under enormous strain,” he says. “New sources of power and new forms of administration and management fill the gap—and create unease and sometimes also injustice, and at the same time create vast new sectors of wealth.”

Those types of social and economic changes also rattled the Roman Republic, leading to the moment in 130 B.C. when politics turned violent. The introduction of a secret ballot meant Roman politicians and political factions couldn’t keep tabs on (or bribe) individual voters. Instead, politicians had to build political brands that appealed to the masses, leading to something akin to modern American campaigning with big promises and populist language aimed at the poor and middle class.

Reforms to the military also meant that service was no longer reserved for the elite, who for centuries used their privilege to demonstrate their loyalty to Rome. For poorer soldiers, however, service became a path to riches. They began to count on the loot, bonuses and gifts of land they received from their often-wealthy commanders meaning that over time the loyalty of the Roman legions shifted from the empire to their generals. These changes set the stage for a new type of politics, one where whipping up the resentments of the lower classes and threatening political enemies with semi-private armies became the norm.

These trends first came to a head in 134 B.C. when Tiberius Gracchus, an elected tribune of the people, proposed a land reform bill that would benefit poorer and middle-class Romans. The way Gracchus went about his reform, however, was an affront to the norms and traditions of the Republic. He brought his law before the Plebeian Assembly without the thumbs-up of the Senate. When his fellow tribune Marcus Octavius threatened to veto the bill, which was his right, Gracchus manipulated the rules to have him stripped of his office. There were other incidents as well, but the most concerning aspect of Gracchus was his fiery, populist language, which whipped his supporters to the edge of political violence. As his power grew, Gracchus began moving through the streets surrounded by a mob of frenzied supporters, a kind of personal militia not seen in Rome before.

Rumors spread that Gracchus was angling to become a king or dictator, and some in the Senate felt they needed to act. When Gracchus stood for a second term as tribune, which was not illegal but broke another norm, a group of Senators and their supporters beat Gracchus and 300 of his followers to death.

It was just the beginning. Over the next century, Tiberius’s brother Gaius Gracchus would come into conflict with the Senate after a similar populist confrontation. The commander Sulla would march legions loyal to him on Rome itself and battle his political rival Marius, the first time Roman troops fought one another. He would then execute and punish his political enemies. In the following generation Pompey and Caesar would settle their political scores using Roman legions, Octavian and Marc Antony would field an army against the Senate before finally battling one another bringing almost 500 years of the Republic to a bloody (and confusing) conclusion.

Watts argues that while the Senate ordered his murder, it was Tiberius Gracchus who let the genie out of the bottle. “What he has to bear responsibility for is he starts using this really aggressive and threatening language and threatening postures. He never resorts to violence, but there’s always this implicit threat. ‘If not for me, things would get out of control.’ And that is different, that was never done before. What he introduces is this political tool of intimidation and threats of violence. Later thinkers say once it’s there, even if others choose not to use it, it’s there forever.”

While life in Rome, with gladiator battles, crucifixions and endless war was violent, for centuries Romans took pride in their republican system and political violence was taboo. “The Republic was free of political violence for the better part of 300 years. People who are politically engaged are not killing each other and they’re not threatening to kill each other. When they disagree with each other they use political means that were created by the republic for dealing with political conflict,” says Watts. “If you lose one of those conflicts, you don’t die and you don’t lose your property and you aren’t sent away. You just lose face and move on. In that sense, this is a remarkably successful system for encouraging compromise and encouraging consensus building and creating mechanisms whereby political conflicts will be decided peacefully.”

So what does the story of the Roman Republic mean for the United States? The comparison is not perfect. The U.S. has had its share of political violence over the centuries and has more or less recovered. Politicians used to regularly duel one another (See the Hamilton soundtrack, song 15), and in the run-up to the Civil War, the ultimate act of political violence, there was the raid on Harper’s Ferry, Bleeding Kansas, and the near murder of Charles Sumner in the Senate chamber. Joanne B. Freeman, author of Field of Blood, a history of violence in Congress before the Civil War, tells Anna Diamond at Smithsonian she found at least 70 incidents of fighting among legislators, including a mass brawl in the House, though they often tried to paper over the conflicts. “It’s all hidden between the lines in the Congressional record; it might say “the conversation became unpleasantly personal.” That meant duel challenges, shoving, pulling guns and knives.”

The better comparison, surprisingly, applies to post-WWII America. Despite periods where the U.S. political system and established political norms have been tested and stretched—the McCarthy hearings, Vietnam, Watergate, the Iraq War—partisan violence or attempts to subvert the system have been rare. But recent events, like changes to filibuster rules and other procedures in Congress as well as increasingly heated political rhetoric give Watts pause. “It is profoundly dangerous when a politician takes a step to undercut or ignore a political norm, it’s extremely dangerous whenever anyone introduces violent rhetoric or actual violence into a republican system that’s designed to promote compromise and consensus building.”

The solution to keeping a republic healthy, if Rome can truly be a guide, is for the citizens to reject any attempts to alter these norms he says. “I think the lesson I take away most profoundly from spending so much time with these materials is basically, yes, we do need to assign blame to politicians and individuals who take a shortsighted view of the health of a republic in order to try to pursue their own personal objectives or specific short-term political advantages.”

The example of the Roman Republic shows the result of not policing those norms and keeping violence in check is the potential loss of democracy. “No republic is eternal,” Watts writes. “It lives only as long as its citizens want it. And, in both the 21stcentury A.D. and the first century B.C., when a republic fails to work as intended, its citizens are capable of choosing the stability of autocratic rule over the chaos of a broken republic.”