Fascism has been back in the news with Donald Trump’s candidacy for the American presidency. His populist claim to speak for the white everyman, along with his menacing leadership style, have brought forth comparisons among this “homegrown authoritarian,” as President Barack Obama has called Trump, and foreign strongmen.

Trump is not a Fascist. He does not aim to establish a one-party state. Yet he has created a one-man-led political movement that does not map onto traditional U.S. party structures or behave in traditional ways. This is how Fascism began as well.

A century before Trump, Benito Mussolini burst onto the Italian political scene, confounding the country’s political establishment with his unorthodox doctrine and tactics and his outsized personality. Mussolini’s rise offers lessons for understanding the Trump phenomenon—and why he was able to disarm much of the American political class.

Many Italians did not know what to make of Mussolini when the former Socialist founded Fascism as an “anti-party” on the heels of World War I. His was an outsider movement, born from the conviction that the establishment parties—along with the political systems they represented, liberalism and socialism—were broken or posed a grave threat to Italy.

A mercurial hothead, Mussolini reveled in his role as a political disrupter. His crisis-mongering platforms contained a confusing blend of socialist and nationalist tenets, trafficking in contradiction and paradox, the better to challenge traditional ideas about politics. “Does Fascism aim at restoring the State, or subverting it? Is it order or disorder?” he taunted Italians in print six months before he took over as prime minister.

His grassroots followers spoke more directly, terrorizing Italy’s hinterland as a prelude to claiming control. Taking Mussolini’s incendiary rhetoric to heart, his blackshirts beat and executed thousands of political opponents—including priests—at rallies and on trains, in shops, schools, and taverns. Everyday violence primed the country for an exceptional outcome: In 1922, Mussolini staged a march on Rome and demanded the post of prime minister from the terrified king.

Italians learned in the 1920s what Americans are learning in 2016: Charismatic authoritarians seeking political office cannot be understood through the framework of traditional politics. They lack interest in, and patience for, established protocols. They often trust few outside of their own families, or those they already control, making collaboration and relationship building difficult. They work from a different playbook, and so must those who intend to confront them.

The authoritarian playbook is defined by the particular relationship such individuals have with their followers. It’s an attachment based on submission to the authority of one individual who stands above the party, even in a regime. Mussolini, a journalist by training, used the media brilliantly to cultivate a direct bond with Italians that confounded political parties and other authority structures and lasted for 18 years.

Trump also cultivates a personalized bond with voters, treating loyalty to the Republican Party almost as an afterthought. It’s why he emphasizes the emotional content of his events—he “feels the love,” or fends off “the haters.” Early on, he introduced a campaign ritual more common in dictatorships than democracies: an oath pledging support to his person, complete with a straight-armed salute. Securing this personal bond is a necessary condition for the success of future authoritarian actions, since it allows the leader to claim, as does Trump, that he embodies the voice and will of the people.

Mussolini’s rise to power also exemplifies another authoritarian trait America has seen during this campaign: The charismatic leader who tests the limits of what the public, press, and political class will tolerate. This exploration begins early and is accomplished through controversial actions and threatening or humiliating remarks toward groups or individuals. It’s designed to gauge the collective appetite and permission for verbal and physical violence and the use of extralegal methods in policing and other realms. The way elites and the press respond to each example of boundary-pushing sets the tone for the leader’s future behavior—and that of his followers.

Mussolini’s testing of Italians through violence showed the weakness of the ruling political establishment. A blend of fear, opportunism, and desire to defeat Italy’s powerful left led many liberals to support Mussolini. Most disliked him but thought he could be mainstreamed or placated once given some power. After he became prime minister, the violence did not abate. Yet key liberal voices such as the philosopher Benedetto Croce and former Prime Minister Antonio Salandra continued to endorse him.

Finally, the Fascists went too far. In June 1924, they assassinated the popular Socialist politician Giacomo Matteotti for accusing them of electoral fraud. Mussolini, denounced by the opposition press as responsible, faced the biggest crisis of his political life. By December, many liberal holdouts had turned against him.

They had waited too long to withdraw their support. On January 3, 1925, Mussolini announced the end of democracy in Italy. “I alone assume political, moral, and historical responsibility for all that has happened.” Mussolini told Parliament. “If Fascism has been a criminal association, then I am the chief of that criminal association...”

Violent language and acts had defined Fascism since its inception. Yet this shocking speech ruined the comforting fable many Italians told themselves: that Mussolini was a sheep in wolf’s clothing, and he would embrace reform rather than revolution once in power. After January 3 and the spate of repression that followed, it was difficult to disassociate the statesman from the squadrist, as Italian elites had tried for years to do.

For over a year now, Trump has been subjecting Americans and American democracy to analogous tests. Actions many see as irrational make chilling sense when considered under this framework: the many racist tweets or retweets, which his campaign then declares a mistake. His early declaration that he could shoot someone on Fifth Avenue in New York and not lose any supporters. His extended humiliation of powerful politicians such as Paul Ryan and John McCain. His attempt to cast doubt on the legitimacy of the American electoral process. His intimation that “the Second-Amendment people” might be able to solve the potential problem of Hillary Clinton appointing judges, presumably by shooting her. This last remark is a sign that Trump feels emboldened in his quest to see how much Americans and the GOP will let him get away with—and when, if ever, they will say “enough.”

Authoritarians usually communicate their intentions clearly. Mussolini certainly did. Trump has been frank about his agenda and the groups he’ll target if he’s elected. “The crime and violence that today afflicts our nation will soon come to an end. Beginning on January 20, 2017, safety will be restored,” Trump said in accepting the Republican presidential nomination. It’s not necessary to label Trump a Fascist to discern the dangers of such rhetoric. There’s no need to see a trajectory to dictatorship to recognize that Trump is testing American decency and the strength of U.S. democracy. The history of Mussolini’s rise coincides with the fall of what had been Italy’s version of a Grand Old Party: the liberal factions that had ruled Italy from Unification onward. They never recovered from their acquiescence to the Duce. Of the many lessons the GOP can take from its experience with Trump so far, this might be the most valuable.