Junius Brutus Stearns’s 1856 painting “Washington Addressing the Constitutional Convention.” (Associated Press)

Danielle Allen is a political theorist at Harvard University and a contributing columnist for The Post. Her Twitter handle is @dsallentess.

In the wake of Tuesday’s Republican debate, here is the question keeping me up nights: When we take barbarism into the very heart of our culture, how can we cure ourselves?

A few weeks ago, in an interview on Fox News, Donald Trump said this about the Islamic State: “We’re fighting a very politically correct war. . . . You have to take out their families.” There are two ideas here: that political realism requires the intentional and gleeful violation of centuries-old laws of war, and that only political correctness prevents us from saying so. During Tuesday night’s debate, the moderators and all of the candidates except for Sen. Rand Paul (Ky.) and former Florida governor Jeb Bush appeared to accept Trump’s dual propositions, and only Paul objected on grounds of principle.

Strangely enough, we are watching an America much like the young republic. I am thinking of the republic that charted a violent and, in essence, genocidal course against Native Americans.

In the Declaration of Independence, one of the colonists’ key grievances against King George was that he was stirring up attacks against the colonies by “the merciless Indian Savages, whose known rule of warfare, is an undistinguished destruction of all ages, sexes and conditions.” Let us put aside for a brief moment the question of whether this complaint was valid as a description of Native Americans in 1776. What matters right now is the realization that for the committee of five who penned the Declaration, and for the members of the Continental Congress who revised it and voted unanimously for it, Trump’s “you have to take out their families” counted as barbarism.

And yet that recognition was insufficient to protect the new republic from behaving in just the way it claimed to abhor. As we know well, the colonists often descended to barbarism against Native Americans, ultimately bringing about the near-total destruction of the indigenous tribes.

Is it politically correct to judge that Native Americans were treated unjustly and that this country failed to live by its clear standards for how to organize the powers of government to effect the safety and happiness of all the people who came under its administration?

Yes, it is. It is “politically correct” in the same way that James Wilson, a lead author of the Constitution, used that phrase in 1793 in a Supreme Court decision, Chisolm v. State of Georgia, about state’s rights.

As a member of the Constitutional Convention, Wilson determinedly argued that the Founders of 1776 had erected a government based on the people, not the states. He is the reason the Constitution begins, “We the People.” In Chisolm, he builds on that idea to propose that we should celebrate not “the United States” but the “People of the United States.” Only the latter expression was “politically correct,” he argued. We ought, he said, to raise toasts to the “People of the United States” as the true object of our efforts and affections.

To be politically correct, in his argument, was to understand the new project of self-governance properly. Why did he emphasize “the People,” rather than “States”? He continues: “A State I cheerfully fully admit, is the noblest work of Man: But, Man himself, free and honest, is, I speak as to this world, the noblest work of God.” His phrase, the “People of the United States,” was politically correct because it captured the right way of thinking about the relationship between the people and its government.

It is equally politically correct, and I am proud to say so, to judge religious freedom, including for Muslims, and respect for the laws of war that protect civilians as indispensable to the foundation of principle on which democratic political institutions rest.

Our argument should not be about whether to be politically correct but about what simply is, in fact, politically correct. Barbarism, in the sense of proposing to destroy the families of Islamic State fighters or terrorists, is politically incorrect in the sense that it is wrong.

How, then, do we cure ourselves of the barbarism that we have taken into the heart of our culture? Can we do anything other than start over, in families, in schools, in neighborhoods, in places of worship, on Facebook and Twitter, talking about the principles of just warfare, exploring the principles of liberty and justice for all, and asking ourselves why the principles of liberty and equality broadly applied have for so long been thought to be the best hope for humankind?

On July 4, 1788, in Philadelphia, at a major celebration of both independence and the new Constitution that had just gotten over its minimal ratification threshold, Wilson was the keynote speaker. He had this to say to his compatriots setting out in hopes of novel political achievements:

“To speak without a metaphor, if the people, at their elections, take care to choose none but representatives that are wise and good, their representatives will take care, in their turn, to choose or appoint none but such as are wise and good also. . . . Of what immense consequence is it, then, that this primary duty [of voting] should be faithfully and skillfully discharged? On the faithful and skillful discharge of it, the public happiness or infelicity, under this and every other constitution, must, in a very great measure, depend. For, believe me, no government, even the best, can be happily administered by ignorant or vicious men.”

Given the poll numbers for the leading Republican candidate, it appears that the problem is with us, the people, and not with this or that candidate. Wilson was right. We, the people, are the foundation of democratic government, and the quality of our government stands or falls with us.

If we are not up to the job of choosing our leaders judiciously, consistent with the core values of our form of government, we will lose our chance at public happiness. We, the people, can cure ourselves of our incipient barbarism only as we have done it before: by calling it out, contesting it and working hard for alternatives.