In November 2016, voters had a chance to repudiate that strain. Instead, Trump was elected president. And four years later, as his first term comes to a close, the power of authoritarianism, and the damage it has done to our republic, has been well documented.

American authoritarianism will flourish if Trump wins the presidency again—and it won’t magically vanish if he loses. Either way, it is critical to understand this strain in our politics, both how prevalent American authoritarianism really is, and what kinds of policies and changes American authoritarians will support when stirred up.

Through four national panel surveys launched the week before the 2016 election and continuing into this year, I sought to answer these questions. (While I focused on authoritarianism, my colleagues in this work, Brian Schaffner from Tufts University and Tatishe Nteta from the University of Massachusetts Amherst, explored the effects of hostile sexism and racism in America, producing their own eye-opening and important findings).

What I found is thatapproximately 18 percent of Americans are highly disposed to authoritarianism, according to their answers to four simple survey questions used by social scientists to estimate this disposition. A further 23 percent or so are just one step below them on the authoritarian scale. This roughly 40 percent of Americans tend to favor authority, obedience and uniformity over freedom, independence and diversity.

This group isn’t a monolith, and these findings don’t mean that 4 in 10 Americans prefer dictatorship to democracy. Authoritarianism is best understood not as a policy preference, the way we talk about lower taxes or strong defense, but rather as a worldview that can be “activated” in the right historical moment by anyone with a big enough megaphone who is willing to play on voters’ fears and insecurities.

When activated by fear, authoritarian-leaning Americans are predisposed to trade civil liberties for strongman solutions to secure law and order; and they are ready to strip civil liberties from those defined as the “other”—a far cry from the image of America as a country built on a shared commitment to liberty and democratic governance.

So what do authoritarians in the US believe? In surveys I found that American authoritarians, compared with non-authoritarians, are more likely to agree that our country should be governed by a strong leader who doesn’t have to bother with Congress or elections. They are more likely to support limiting the freedom of the press and agree that the media is the enemy of the people rather than a valuable independent institution. They are also more likely to think the president should have the power to limit the voice and vote of opposition parties, while believing that those who disagree with them are a threat to our country—a concerning trend as we head to the polls this year.

American authoritarians fear diversity. They are more likely to agree that increasing racial, religious and ethnic diversity is a clear and present threat to national security. They are more fearful of people of other races, and agree with the statement that “sometimes other groups must be kept in their place.”

To many Americans, steeped in the ideals of the Declaration of Independence and the core set of constitutional freedoms embodied in the Bill of Rights, these findings are undoubtedly bewildering. But I am not the sole researcher to report them. Many others, led in the United States by Stanley Feldman, Marc Hetherington, Jonathan Weiler and Karen Stenner, have written for years about American authoritarianism and its activation in academic books and papers. My own findings, which build on their work, are gathered in the index of American authoritarian attitudes contained in a new book on the history of authoritarian activation in America.

These results explain, in part, how Trump can remain popular with his base despite any number of policies that would have been considered unconstitutional, anti-American and perhaps even criminal in the past by members of both parties. He has sent paramilitary forces from the Department of Homeland Security to quell nonviolent protests, looked the other way when a foreign power interferes in American elections, celebrated the wounding of a journalist by police as “a beautiful sight,” and spent an election year casting doubt on the very basis of our democracy, the electoral system, rather than working to protect it—all without eroding his main base of support.

American thinkers have been alert to the dangers of authoritarianism stoked by demagogues since the nation’s founding. In Federalist 63, James Madison warned of the danger the “infection of [the] violent passions” stoked by “the artful misrepresentations of interested men” posed to the future of the Republic. In a 1927 Supreme Court opinion, Justice Louis Brandeis cautioned that: “Those who won our independence believed … that fear breeds repression; that repression breeds hate; that hate menaces stable government.” The historian Richard Hofstadter, in 1964, labeled the weaponization of fear to attain power as the “paranoid style in American politics,” describing it as an “old and recurrent phenomenon in our public life” that “has a greater affinity for bad causes than good” and “has been frequently linked with movement of suspicious discontent.”

The political path to galvanize American authoritarianism is also well worn and documented. First, purveyors of the paranoid style conjure an “other.” Second, this other is described as different from mainstream Americans, and identified as a clear and present threat to majoritarian values and traditions. Third, the paranoid leader stokes fear that a hidden conspiracy to undermine mainstream values is afoot and alleges that the other is behind it—activating American authoritarians. Finally, in its most virulent manifestation, growing fear of the other is manipulated to rationalize actions that violate fundamental values, norms, laws and constitutional protections guaranteed to all Americans.

This path reads like the playbook guiding the Trump administration and campaign. Much of it was on view at the Republican National Convention: “They want to destroy this country,” Kimberly Guifoyle bellowed from the podium. Donald Trump Jr. warned: “Joe Biden and the radical left are also now coming for our freedom of speech, and want to bully us into submission.” American history is littered with examples of what happens when messages like these stir up their intended targets.

Our nation’s egalitarian, democratic aspirations have always competed for supremacy with a darker tradition rooted in authority, obedience and the hegemonic enforcement of majoritarian interests and norms. But it has never confronted a challenge like this. Trumpism is McCarthyism on steroids, and its full expression menaces the stability of our democracy. A country where authoritarian ideals are ascendant, and remain ascendant, is no longer a democracy. It is on the road to fascism, or what some now call, euphemistically, illiberal democracy.

But a country that can look clearly at its own authoritarian impulses, understand them and find ways to address them is a democracy that can survive and flourish.

Let me be clear: Our fellow Americans, including our authoritarian neighbors, are not the enemy. The enemies of democracy are self-interested men and women who exploit fear to secure and expand their power. Fear activates the reservoir of intolerance that resides across ideological and partisan divides. And it dupes some of us into demanding uniformity over diversity, denigrating our neighbors, and turning our back on the very motto inscribed on the Great Seal of our Republic in 1782: e pluribus unum.

Democracy is fragile. As John Quincy Adams wrote in 1814, “Democracy never lasts long. It soon wastes, exhausts and murders itself. There never was a democracy yet, that did not commit suicide.”

In November, we have a choice: freedom or fear. If we choose freedom, our work is not done. Once stirred and embraced as deeply as it has been over the past four years, authoritarianism will not simply dissipate with the results of an election. We need to take action personally, institutionally and socially to rebuild the guardrails of democracy that protect our Republic from careening off the road into the gutter.

Personally, we need to stop othering each other. No more schoolyard labeling of one another as “libtard,” “snowflake,” or “deplorable.” No more reveling in the drawing of differences between us and them. There is no “enemy within” except the self-interested misleaders who exacerbate our problems. The real enemy is ignorance, disinformation and the lure of simple authoritarian answers to complex problems.

Institutionally, we need to rebuild faith in the institutions of government and democracy by demanding that our leaders are constrained by the rule of law and our fundamental constitutional principles.

Socially, we must confront and make peace with our history. We have much to be proud of as Americans, but we also have a history that needs to be confronted. Projects like Trump’s 1776 Commission, designed to whitewash that history, point in the wrong direction. Reconciliation of our past transgressions strengthens us as a people.

These may seem like Pollyannaish prescriptions for a Mad Max world. They are not. These are some of the necessary steps to protect and defend our birthright as Americans. And I am not the first to suggest them.

In 1950, taking McCarthyism head on while others demurred, Republican Senator Margaret Chase Smith delivered a more pointed articulation of these principles in her “Declaration of Conscience.” She said: “It is high time that we stopped thinking politically as Republicans and Democrats about elections and started thinking patriotically as Americans about national security based on individual freedoms. It is high time that we all stopped being tools and victims of totalitarian techniques that, if continued here unchecked, will surely end what we have come to cherish as the American way of life.”