With the fall semester starting, I am preparing once more to teach undergraduate and graduate students at Pepperdine University about American political thought. But this year I find myself compelled to revise my syllabus in a way I never dreamed necessary—I am including a section on fascism.

When I was a graduate student at the University of California at Berkeley in the early 2000s, I served as a teaching assistant for various courses in American politics and they inevitably began with the same spiel: American political thought has largely resisted ideologies like communism and fascism. These systems of thought might therefore be safely put aside when studying the United States. Few foresaw then the meteoric rise of Donald Trump. His ascendancy to the Republican presidential nomination means many things to many different people. But for professors of American politics it means rethinking the syllabus from the ground up.

Composing a syllabus in political science is itself a political act—which societal problems are important? Which can be glossed over? How should a political movement, party, or candidate be conceptualized? Describing political reality often entails entering the political fray. For example, every year when I teach about race in the United States, I have students who find Michelle Alexander’s thesis that Americans live in a system of racial caste not only inaccurate but offensive. They do not see why it should be included on the syllabus at all. At the same time, I have students who strongly object to describing the U.S. as a colorblind meritocracy. The very way in which political life is conceptualized and described is subject to controversy that is, in turn, political.

Trump’s effect on writing a syllabus has been to make this political controversy even more poignant. This is because for the last 50 years, most political-science professors have relied on what has become a standard framework. It comes from Louis Hartz, a Harvard professor, whose famous thesis states that both the left and the right in the United States are dominated by what he dubbed the “liberal tradition” (“liberal” in the older sense of the word and not as the opposite of “conservative”). The liberal tradition is an ideology that affirms individual rights, due process of law, and a separation of powers in government. Hartz believed this tradition was so ingrained in American culture that there had never really been a need for a distinct liberal party or movement but simply what he called “the American Way of Life.” On this view, ideological conflict in the United States has primarily been an intramural quarrel among conservative liberals, centrist liberals, and liberal liberals.

The dominance of the Hartzian paradigm is evident in the way the top textbooks in American politics (used to teach literally thousands of undergraduates every year) uniformly omit any extended analysis of fascism, communism, or any other non-liberal ideology. This omission was certainly standard practice among political scientists who taught introduction to American politics courses at Berkeley. What it allowed professors to do was paint the full ideological spectrum in the U.S. using the same brush. Everyone in America was more or less on the same side. No harsh lines needed to be drawn. Of course, whether intended or not, this assumption implied a kind of liberal triumphalism. Other ideologies could be ignored because all American roads led to one final destination—liberalism.

Yet, the unprecedented dimensions of Trump’s own politics have upset this familiar landscape. Suddenly professors of political science will need to make controversial classifications. Many professors will be forced out of comfortable habits of mind this fall.

This is made clear by observing Trump through the lens of my own branch of political science—political philosophy. Political philosophy studies the basic concepts, arguments, and traditions that inform political life. It can help us understand how Trump represents a radical break from three of the basic commitments of the liberal tradition—individual rights, due process of law, and separation of powers.

First, consider Trump’s willingness to attack two of the cornerstone rights of liberal democracies—the freedom of religion and the liberty to express criticism, especially through a free press. Trump has made a series of comments on the campaign trail calling for the state to close down mosques, register Muslims in a national database, and conduct intense surveillance. Trump has also gone further than any modern candidate in trying to muzzle the press. When he has not liked a publication’s particular coverage, he has revoked its press pass, banning journalists working for publications across the Left-Right spectrum, including, The Huffington Post, Politico, The Washington Post, and National Review.

Needless to say, for an aspirant to the highest office in a democracy to shut out the press whenever it becomes critical sets a dangerous precedent. A similar point could be made about Trump’s penchant for ejecting protesters from his rallies and sometimes inciting his angry crowds to violence against lone dissenting voices.

Perhaps Trump’s most extreme negation of liberal rights to date has been his suggestion that the U.S. military use violence against the families of enemy combatants. This is not only a clear violation of the Geneva Convention, but also an utter repudiation of the basic assumption behind American government—namely, that all human beings not directly engaged in warfare against a democratic state are entitled to certain basic rights, the most fundamental of which is the right to life.

Trump’s general disregard of liberal rights is closely tied to his dismissal of a second major liberal norm: due process of law. Liberals believe legal procedures are centrally important because they ensure fair treatment and protect against abuses of power. Yet Trump’s entire candidacy at times seems an expression of exhaustion and anger with legal procedure.

For example, Trump is skeptical of the legal procedures of elections—claiming that if he loses the election in November it will be because it was “rigged,” joking that extralegal, violent means might be necessary to stop Hillary Clinton, and having the dubious distinction of being the first major American candidate to call on a foreign power (Russia) to illegally spy on his political adversary. These are only a few examples of Trump’s wider scorn for procedure, and persistent desire to untie the Gordian knot of the law by hacking it to bits with a sword.

Finally, there is the liberal tradition’s separation of government powers and skepticism of strongman government. Needless to say, Trump’s glorification of executive force over other branches of government implies disrespect for this long held liberal value. Notoriously, Trump has attempted to cast a shadow on the legitimacy of the courts by arguing that a judge presiding over a civil fraud lawsuit against Trump University was incapable of conducting a fair trial due to his racial identity.

Trump has also treated Congress like a site for strongman executive reform, showing little patience for compromising with Congressional leaders. So he has gone to unprecedented lengths to undermine high-ranking representatives of his own party in an election year by implying support for insurgent candidates who show him unquestioning deference. Indeed, one might infer from Trump’s political actions that his ideal of government is one of unencumbered, single man executive action, with a toothless judiciary and fawning Congress along for the ride.

In these and many other ways Trump has utterly broken from the Hartzian liberal tradition and its “American way of life.” By doing so he forces many professors of American politics into new terrain when trying to classify his ideology for their students.

Unfortunately, professors looking to identify the philosophical logic underlying Trump’s political attitudes can do little better than read Carl Schmitt, the infamous Nazi legal theorist. Schmitt is mostly known for launching a scathing philosophical attack on liberalism in the midst of Germany’s short-lived parliamentary Weimar Republic.

At the center of Schmitt’s political philosophy was what he called the “friend” versus “enemy” distinction. According to Schmitt, all human politics was fundamentally about the difference between the friends of a given political order and its enemies. Politics was not foremost about securing rights or justice, but about clearly recognizing the existential threat enemies posed to a political community. A healthy polity was tireless in identifying its enemies, and the central role of the state was to protect and preserve its people against foes both inside and outside the country.

The problem with liberalism, according to Schmitt, was that it was mushy and confused when it came to friends and enemies. This was not only because liberalism was entangled in a naïve cosmopolitanism, in which all peoples could be friends via a respect for human rights, but also because liberalism too often confused political life with economic relationships in a market. Liberalism thus continually became hopelessly muddled and weak on the question of who its real enemies were.

The inability of American liberals on both the Left and the Right to know their enemies and deal with them using proper firmness is, of course, one of the few consistent assumptions of Trump’s political ideology. Indeed, Trump publicly voiced this view as far back as 1990, when, in an interview with Playboy, he expressed admiration for the Chinese Communist government’s firm hand in “putting down” pro-democracy protesters in Tiananmen Square. As Trump put it:

When the students poured into Tiananmen Square, the Chinese government almost blew it. Then they were vicious, they were horrible, but they put it down with strength. That shows you the power of strength. Our country is right now perceived as weak.

In the same interview, Trump criticized then-Republican President George H. W. Bush for advocating a “kinder, gentler America,” reasoning that “if this country gets any kinder or gentler, it’s literally going to cease to exist.”

In this way, Trump’s ongoing infatuation with strongman power is evocative of Schmitt’s political philosophy. What Trump admires in Vladimir Putin’s authoritarian use of power (or that of the Chinese Communist state) is a similar political vision not found in American liberalism. Namely, that the ultimate goal of politics is to show strength against enemies, and not to be weakened by procedure, power sharing, and sentimental delusions of universal rights.

Many people have noted that Trump is inconsistent on all the policy debates that matter most to the traditional Left and Right: reversing his position on abortion, welfare programs, and even which party to endorse (in 1990 he said if he ever ran for president it would be as a Democrat). But he has rarely—if ever—renounced his view of the world as divided between friends of the nation and its racial, ethnic, ideological, and religious enemies.

In this regard, Trump’s obsession with weakness and humiliation brought on by liberalism is a page straight out of Schmitt’s book. “Only a weak people will disappear,” Schmitt wrote of liberalism in 1927. “We need fighters in this country. We don’t need weak people. We have enough of them,” Trump declared in 2016.

Viewed against the backdrop of Schmitt’s thought, it is not so surprising to read that the top Nazi leader in the United States recently gushed that Trump’s candidacy presents a “wonderful opportunity” for white nationalists to show their “views are not so unpopular” as people think. Like it or not—fascism has arrived in America.

Of course, a skeptic could always object that Trump is no fascist by pointing to certain historical disanalogies. After all, Trump has not formed a separate fascist party or put together paramilitary forces like Mussolini did. That skeptic might also note that Trump on the campaign trail enthusiastically endorses certain rights (such as the Second Amendment right to bear arms). Doesn’t this mean Trump can be safely classified as yet another in a long line of right-liberals? If this were the case, professors might go back to business as usual when teaching about American political thought.

Yet this skeptic’s criticism would be flawed. The problem with this response is not only that it misses Trump’s flagrant and unprecedented violations of liberal values, but also the fact that Trump is not a philosopher attempting to achieve consistency, but an opportunist willing to cobble together an assortment of ideas to make a bid for power. Here the similarity to fascism again becomes apparent: Mussolini was also striking for his ideological opportunism and indifference to theoretical consistency.

The lesson of all this is that the rise of Trump has shattered the Hartzian illusion that American politics is one big, happy, liberal tradition with occasional family spats. Professors of American politics will need to venture much further afield if they are to properly map the actual contours of American ideology.

Indeed, the fact of the matter is that the Hartzian lens was never really an adequate paradigm for studying American ideology. As Rogers M. Smith, a professor of political science at the University Pennsylvania, persuasively argued two decades ago, the United States has always been home to multiple traditions of political thought, from various democratic alternatives to liberalism, like civic republicanism, to less savory ideologies of racial and gender hierarchies. Hartz’s vision of America was always too sanitized.

Yet all this leaves the American professoriate in an awkward lurch. The Hartzian view of America had been a comfortable way to teach—not inspiring the ire of either side of the culture war. Professors could pose as above the ideological fray. But to point out the increasingly indisputable fact that Trump has radically broken from some of the basic norms informing American political institutions and exhibits clear authoritarian tendencies is to court controversy. There is no completely comfortable way to teach this reality in an election year.

If there is something to learn from the rise of Trump, perhaps it is that the U.S. has always been more conflicted and ideologically diverse than the Hartzian picture allowed. The one lesson all teachers of American politics should take away from this election year: Hartz’s approach must be left behind in order to take a longer and harder look at what America has been—and might yet become.