Casual observers of our friends across the pond like to say that the British don’t have a constitution. That’s not quite right. They do have one, but unlike their American cousins, theirs isn’t spelled out in a single document. Instead, the British constitution is an amalgam of domestic and international law, precedent and tradition, the product of 1,000 years of history.

While the United States does have a single document called “The Constitution,” with an uppercase T and C, the American system also presumes nonconstitutional values and customs that are just as vital, if not more vital to the health of our democracy. The British philosopher Edmund Burke, who was widely read by our well-read founders, tells us why: “Custom is to be regarded with great deference, especially if it be a universal custom,” he wrote, “for there is some general principle operating to produce customs that is a more sure guide than our theories.”

The American founders believed that the principles that should govern a nation are rooted in customs that are themselves rooted in objective realities. As John Courtney Murray, S.J. once observed, the founding declaration, “We hold these truths,” necessarily implies that objective truths exist and that such truths embody “a natural law that makes known to all of us the structure of the moral universe” and binds us “in a common obedience.”

Yet how many Americans still believe that? The more common view seems to be that truth is more like something I create rather than something that we inherit or discover. Has this relativism, long operative in other realms of American life, now entered our politics in a dramatic, new way? Is the new post-factual politics simply one part of a larger cultural shift, one we made long ago? It is a relatively short walk from “there are no objective truths” to “there are no objective facts.” Have we taken those steps? If so, then the free press that our constitution presumes and requires is seriously threatened.

The founders knew, as Thomas Jefferson wrote, that “a despotic government always [keeps] a kind of standing army of news writers who, without any regard to truth or to what should be like truth…put into the papers whatever might serve the ministers.” Jefferson believed that the pursuit of truth, especially those empirical facts that are the first instance of truth and the foundation of good journalism, is the surest guard against tyranny, so much so that he once said that if he had to choose between newspapers without a government, or a government without newspapers, he preferred the former.

Yet many Americans now find such sentiments quaint or naïve. In our contemporary politics, facts are not stubborn but elastic things: You have your facts, I have my “alternative facts,” statements not subject to painstaking empirical verification, but simple ideological confirmation. That is itself troubling. Ideologies are little more than questions that answer themselves. The bigger worry, however, is that this world of “alternative facts” seriously undermines the ability of the press to do its constitutional job. When that happens, we’re one step closer to a government without newspapers.

Where does this end? Some think, as David Brooks recently wrote in The New York Times, that “we are seeing the rise of fascism, a new authoritarian age.” But, he adds, “that gets things exactly backward. The real fear in the Trump era should be that everything will become disorganized, chaotic, degenerate, clownish and incompetent.”

Mr. Brooks is right. We more likely face destabilizing, constitutional confusion, than brute authoritarianism. But I suspect that’s not simply the result of the last election. The seeds of the post-factual crisis were planted long ago, amid a greater confusion about the truths we hold, a situation that politicians skillfully manipulated but we the people created.

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This article appears in February 6 2017.