America's top cop is a rightwing culture warrior who hates disorder. What could go wrong?

Maybe the 1960s never ended. Police, protesters and rioters once again fill our rage-filled streets and television screens. Amid a pandemic that has already claimed over 100,000 lives, a cultural divide that burst into flames more than a half-century ago is back – and burning furiously.

Earlier this week, Donald Trump seemed to morph into Richard Nixon, America’s self-proclaimed “law and order” president who resigned in disgrace. The cameras rolled as a Bible-brandishing president threatened to send US troops into America’s cities. As Trump stood in front of an Episcopal church near the White House, teargas canisters and flash-bang grenades exploded nearby.

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In his inaugural address in 2017, Trump vowed to restore what he characterized as American greatness, strength, and safety. In William Barr, the US attorney general, Trump has a powerful and determined partner. It was Barr who personally ordered military police to clear peaceful protesters from around the White House, and Barr who is reportedly advocating an intense “flood the zone” show of authority. “The president sees Barr as the ‘bad cop’ he can unleash if states and cities don’t get their act together,” an administration official told the Daily Beast.

Both men aim to turn back the clock to a time when everyone “knew their place”. But where Trump has been a bumbling, self-interested and ideologically erratic leader – a weak man’s strongman – Barr is smart, dedicated and disciplined. He understands how to wield power and holds a consistent worldview. He’s an aggressive advocate for executive power and the police – who happens to be America’s top law enforcement officer at the same time as unrest roils the country.

“Barr is vastly more intelligent than Donald Trump,” Stuart Gerson, a former colleague of Barr’s, recently told the New York Times Magazine. “What Trump gives Bill Barr is a canvas upon which to paint. Bill has longstanding views about how society should be organized, which can now be manifested and acted upon to a degree that they never could have before.” (Gerson was my boss when I worked at the US Department of Justice from 1990 to 1992. Barr was head of the department from November 1991 to January 1993.)

Trump and Barr are close in age. Both grew up during the Vietnam war and the 1960s- and 1970s-era unrest. But where young Trump’s “personal Vietnam” involved dodging syphilis, avoiding the draft, “bone spurs” and apprenticeship in his father’s growing real estate empire, Vietnam, for young “Billy” Barr, was different. The war was part of his family’s reality.

Barr’s older brother was in Vietnam, fighting in the navy. Barr’s father had served in the army during the Second World War and was a member of the Office of Strategic Services, the forerunner to the Central Intelligence Agency.

As a Columbia undergraduate, Barr stood fast against the anti-war protesters who sought to bring the university to its knees. Back then, the operative divide was “Staten Island v Scarsdale” – conservative, often Catholic, students from the blue-collar New York City outer borough versus liberal, often Jewish, students from affluent suburbs. Barr, though far from working-class, was firmly planted in the first camp.

At the time, radical leftwing activists such as Berkeley’s Mario Savio argued that people of conscience must throw themselves against the machinery of the state. Barr, in contrast, saw himself as holding the line against anarchy and disorder. When protesters attempted to storm the university library, Barr and a group of counter-protesters blocked them. The standoff, according to the New York Times, was resolved by a massive fistfight. The counter-protestors won.

Ultimately, however, Barr’s side of the student culture war lost. Nixon, though an anti-communist, knew the American public’s appetite for the war was rapidly depleting. He pulled America out of Vietnam after 20,000 US soldiers were killed on his watch.

When Saigon fell and the draft ended, the two sides of the culture war retreated to their respective corners. Leftist students started their “long march through the institutions” – academia, journalism and the cultural sphere.

And Barr and the pro-Vietnam crowd started their own long march, too. Barr briefly served in the CIA as an analyst and then in the agency’s legislative counsel’s office, where he met George HW Bush, then helming the agency. When Bush was later elected president, in 1988, Barr joined the administration and rapidly rose to the top of the justice department, where he served his first tenure as attorney general. A profile at the time described Barr as a “bookish-looking son of educators who speaks with a muted New York accent”, and extremely effective.

During the 1992 Los Angeles riots following the Rodney King verdict, Barr argued that “our system is fair and does not treat people differently”. He conceded that “our national criminal-justice system is a diverse [and] broad one”, with cases of individual bias, but that “taken in its totality, the system seems to operate fairly”. He blamed the riots mainly on opportunistic gang violence.

After two days of rioting, Bush and Barr invoked the Insurrection Act at the request of California’s Republican governor, Pete Wilson. The statute is a rarely-used provision that permits the president to use federal military forces for domestic law enforcement, which is normally illegal. Together with the national guard, the US army and marines deployed to LA and helped restored order.

Today the US faces a situation akin to the 1992 riots, not to mention the 1960s clashes over Vietnam. Barr and the pro-Vietnam crowd lost that battle, but hoped to win the war. Now, in the Trump presidency, history has offered Barr a kind of do-over.

In the New York Times, Gerson, Barr’s former justice department colleague, characterized Barr as “hierarchical” and “authoritarian” in outlook, committed to the premise that “a top-down ordering of society will produce a more moral society”.

In speeches, Barr, a traditionalist Catholic, has railed against “militant secularists”, who seek “to mitigate the social costs of personal misconduct and irresponsibility”.

Barr and many conservatives of his generation remember the 1960s cultural revolution as a kind of traumatic rupture in US history – a Pandora’s box that unleashed decadence, sexual permissiveness and rebelliousness, and led to the atomization of society and the decline of the family unit. The results, as they see it, were leftist militancy, drug addiction, out-of-wedlock childbirth and a decoupling of religion from society. For a certain kind of conservative, undoing that legacy has been a decades-long political project.

In the long term, Trump’s real legacy as president may be the stamp he puts on the federal judiciary. The judges he has appointed – 193 so far, including two supreme court justices – are already wading into fierce legal disputes concerning abortion, immigration, sexual orientation and other issues. Their rulings will reverberate long after Trump leaves office. His judicial nominations are frequently drawn from the ranks of the Federalist Society, a conservative legal organization founded in the early 1980s at the Harvard, Yale and University of Chicago law schools as a counterweight to what its members perceived as the liberal orthodoxies prevalent at the leading law schools.

The Federalist Society and its supporters, including Barr, frame themselves as favoring strict readings of the constitution; in practice, however, they have frequently pushed for the expansion of executive power. One particular target of their hostility is the 1973 War Powers Act, Congress’s attempt to reassert itself after the debacle of Vietnam and rein in the war-making powers of the president.

In 2001, looking back at the Gulf war and his advice as attorney general to then president George HW Bush, Barr recalled: “I believed that the president did not require any authorization from Congress, and I believed that the president had constitutional authority to launch an attack against the Iraqis.”

Now the battlefield is urban America. Trump has threatened to use the US military to quell unrest. This week an army airborne division was moved near Washington DC, for a possible deployment as a militarized adjunct to domestic law enforcement, though the Pentagon reversed the decision.

In his public statement about the current unrest, Barr has said: “It is time to stop watching the violence and to confront and stop it.” He added that “violence instigated and carried out by antifa” is “domestic terrorism and will be treated accordingly”.

Perhaps everything has come full circle: for Barr, this is one last fight to get it “right”.

• An attorney in New York, Lloyd Green was opposition research counsel to George HW Bush’s 1988 campaign and served in the Department of Justice from 1990 to 1992