When the complete history of the decline and fall of the American nation comes to be written, the turning point toward failure will not be recorded as the election of Donald Trump in 2016. It will be found among the events of 1968.

The young new year is a suitable occasion to recall the ways Americans began to come apart exactly 50 years ago.

Forces unleashed back then by angry protesters and resentful defenders of traditional ideals culminated decades later in the division of our people into “red” and “blue” warring tribes, with no cultural intermediaries left to speak of.

The year 1968 started badly in late January with the Tet Offensive in South Vietnam. It got worse with President Lyndon Johnson’s abandonment of presidential responsibility in March. It sank to unprecedented lows with the assassinations of the Rev. Martin Luther King Jr. in April and Robert Kennedy in June.

The overt expression of cultural decay came in presidential politics. The Democratic Party split bitterly and meanly. The 1968 Democratic National Convention turned into a violent shambles unlike anything experienced since the founding of the country. Republican Richard Nixon as a result just barely won the presidency by shrewdly appealing to the fears and hopes of those called “deplorables” by Democrats all these years later.

Nixon, it’s worth recalling, called them the “Silent Majority.”

But, as always, politics reflected culture. In 1968, the baby boom generation came of age and started making its mark. The “Me Generation” had arrived. The men, sons of the “Greatest Generation,” did not want to fight communism in Vietnam as their fathers had fought fascism in Germany, Italy and Japan. The women wanted new social equality and freedom concerning sex, marriage and work that their mothers had never dreamed of.

The “Protestant ethic” of self-discipline and personal responsibility was rejected by many boomers. In its place was thrust forward a culture of entitlement and “self-actualization” as the New Jerusalem for America. Duty to family and country was old-fashioned, not “hip,” while “if it feels good, do it” became a norm for progressive minds to embrace.

Reflecting on his times in 1968, Irving Kristol presciently wrote: “Who can deny that, in the United States today, as never before in its history, there is a vast unease about the prospects of the republic? … None of [our] problems, taken by itself, seems insoluble. But taken together, they constitute a condition and are creating habits of mind that threaten the civic-bourgeois culture bequeathed to us by Western civilization.”

On the night of Jan. 31, 1968, all across South Vietnam, communist soldiers swarmed out of jungles into towns and cities, hoping to provoke the collapse of the South Vietnamese government. As the recent Ken Burns documentary affirmed, this Tet Offensive was a massive military defeat for the communists.

But the American press, as surprised as everyone else but more unnerved, declared it a failure for American arms, casting doubt on the viability of the entire war. However honest the misunderstanding, it was an early instance of what today some call “fake news.”

When Walter Cronkite on national television expressed his opinion that the war was unwinnable and so should be abandoned, Johnson said: “I’ve just lost Middle America.”

Johnson was certainly losing his nerve, as the boomers chanted “Hey, hey, LBJ, how many kids did you kill today?” The president won the write-in Democratic primary in New Hampshire some weeks later, but Minnesota’s U.S. Sen. Eugene McCarthy, running as an antiwar alternative, came in a respectable second, which became the story of the day.

Not to be outflanked, Bobby Kennedy jumped into the race as an Old Testament prophet calling for judgment on a failed people, undone by their support for the war in Vietnam and their tolerance of poverty and racism.

The once invincibly ambitious and imperious Johnson quickly abandoned ship, announcing that he would not seek another term as president.

This dereliction of duty sent shivers of uncertainty through every American cultural nerve. Everything was up for grabs intellectually and morally. There was no trustworthy foundation. No longer was there unquestioned affirmation of those ideals that (1) had supported our national identity, our self-respect and our patriotism, and (2) had given us, as a community of citizens in common cause, a purpose to make the country better and better in the days and years to come.

The sense that America was losing its way was painfully confirmed by the assassination of King in Memphis on April 4.

Riots among African-Americans, which had been seen by then for several summers, broke out anew.

Fifty years later, anger over unjust killings of black men fuels the Black Lives Matter movement.

In 1968, two African-American Olympic sprinters stood on the victor’s platform in Mexico City, as “The Star-Spangled Banner” was played, with a gloved hand raised in the “Black Power” salute of defiance against white privilege. Today, NFL players defy convention by taking a knee when the national anthem is played.

The deep cultural indictment expressed by these tragedies and conflicts was and is an accusation that victimization — not equality of opportunity — is the ultimate American truth. We are not a godly people who should be patriotic and thankful for the blessings of liberty but only the heirs to plunder justified by the racism, misogyny and homophobia of cisgendered patriarchs.

Kennedy’s campaign, more expressly than McCarthy’s, put on the table a compelling sense that America was in need of redemption. Kennedy appealed to the Old Testament leanings of our Protestant heritage; our vocation as a people was to “make a highway for the Lord in the wilderness.” If we went astray, we would be punished.

When he was killed, it was yet another blow to the idea of “American exceptionalism” as a force for good.

Perceived failure in Vietnam sure made it look as if we had lost God’s blessing. Never before had the U.S. lost a war. And the murder of two idealists would not have happened if we were really that godly “city upon a hill” John Winthrop had envisioned in 1630 as his Puritans sailed into Boston harbor.

Here was a cultural opening for the left. The alternative vision of what America was to be had already been set forth by Students for a Democratic Society in the 1962 “Port Huron Statement,” which grandly proclaimed: “We would replace power rooted in possession, privilege, or circumstance by power and uniqueness rooted in love, reflectiveness, reason, and creativity … . We are people of this generation, bred in at least modest comfort, housed now in universities, looking uncomfortably to the world we inherit.”

The SDS founders deconstructed the concept of America by associating the nation with wrongdoing: “The declaration ‘all men are created equal …’ rang hollow before the facts of Negro life in the South and the big cities of the North. The proclaimed peaceful intentions of the United States contradicted its economic and military investments in the Cold War status quo. … Not only did tarnish appear on our image of American virtue, not only did disillusion occur when the hypocrisy of American ideals was discovered, but we began to sense that what we had originally seen as the American Golden Age was actually the decline of an era.”

Elements of this ideology were eagerly picked up in 1968 by McCarthy and Kennedy supporters. Students and intellectuals had rallied to their campaigns. With the Yippies in the lead, college-educated baby boomer protesters took on the power structure of the Democratic Party during the party’s August convention in Chicago.

The party’s old-line liberals, who had brought the country out of the Depression, defeated the fascists and stood up to the Stalinists were worriedly on the defensive. Events were spinning out of control. Chicago’s boss, Mayor Richard Daley, called out his police to beat up the demonstrators and show them who was in charge.

Inside the hall, the old-timers carried the day and nominated Hubert Humphrey for president. The young cultural rebels and their mentors waited for another day. In 1972, they would take over the Democratic Party behind George McGovern and turn it toward what we have today — a party of the left espousing an entitlement society of “safe spaces” for its client constituencies and marginalization for the rest — the Democratic Party of Barack Obama, and still more of Bernie Sanders, Elizabeth Warren and Keith Ellison.

Back in 1968, as the Democratic establishment was being challenged by the “New Left,” Alabama’s George Wallace brought forth a Southern-based movement from the right offering solidarity with working-class whites. In time, this constituency, expanded to the mountain West and the industrial North, would become Donald Trump’s devoted base.

For their part, the Republicans in 1968, skippered by Nixon, moved to exploit the fissures among the Democrats and the anxieties of the white middle class. Under his so-called Southern strategy, Nixon successfully brought Southern whites into the Republican Party. He also began to lure northern blue-collar whites away from the Democrats and so laid the cultural foundation for today’s Republican Party in Southern and Western states, small towns, and rural areas.

Take away the votes of residents in Los Angeles and New York City, and Donald Trump would have won the nationwide popular vote in 2016.

On the cultural front, 1968 specialized in dystopian movies: “2001: A Space Odyssey” foretold artificial intelligence taking over the cosmos from humans; “Planet of the Apes” predicted that humans would destroy their civilization, letting beasts take over; and “Rosemary’s Baby” offered the unnerving vision of satanic forces right next door.

That momentous year also saw the beginning of a transformation in colleges and universities, away from providing American society with moderate and centrist leadership, when Mark Rudd led the takeover of Low Library at Columbia University. Rudd was an SDS leader. In line with the Port Huron Statement, he believed that “the university could serve as a significant source of social criticism and an initiator of new modes and molders of attitudes and that … universities are an overlooked seat of influence.”

Today, 50 years later, tenured professors serve as the central committee of our would-be New Left ruling class. Higher education has become a cultural space protected against disobedient threats arising from free speech and free thought.

America was once great because Americans were once “liberal” in an old-fashioned sense. They affirmed the rule of law and fair process; they valued equal opportunity; they trusted each other, just enough; they were idealistic and optimistic. The center held. Both right and left were kept at the margins of politics. Compromise and collaboration carried the nation forward, even if only one small step at a time.

Today we are a disheartened and bitterly divided people. And our travails started back in 1968.

Stephen B. Young, of St. Paul, is global executive director of the Caux Round Table, a network of business leaders working to promote a moral capitalism.