In the weeks since 8 November, when Donald Trump won a majority of the electoral college despite losing the popular vote by three million, the culture of informed, participatory, representative democracy has taken one hit after another.

Before our eyes, the American republic, that most durable of representative democratic experiments, is morphing into something unrecognisable. At the federal level, the mediating, moderating institutions are withering away, leaving an abyss in the centre of US politics that Trump threatens to fill with a toxic appeal to race and religion baiting. Day after day, one reads reports of hate crimes and a surge in incivility – of Muslim women attacked in the streets, of swastikas painted on buildings, of Latino kids in schools being taunted about the wall that Trump has promised to build on the Mexican border. The Ku Klux Klan has rallied in several cities. “Alt-right” groups – some of which share members with neo-Nazi organisations – have held triumphalist events in Washington, DC.

Through it all, Trump has spent his time not trying to show that he will be a unifying president, not condemning this wave of violence, but instead holding his own rolling series of triumphalist rallies designed to shore up his personality cult.

Trump is only nominally a Grand Old Party Republican. His power derives not from understanding the ins and outs of party politics, playing by the long-established rules of a two-party system, nor from having studied the workings of the constitution, nor from any specialised legal or diplomatic knowledge. Rather, it stems from direct appeals to “the people”. Though a billionaire, Trump has fashioned himself as a far-right populist, a leader who speaks to the sensibilities of the mob with no time or patience for nuance.

He has enthusiastically endorsed “the torture” against terrorism suspects; collective punishment and executions; religious tests of entry for would-be immigrants; registries of Muslims; the jailing of his political opponents; clampdowns on free speech and on the functioning of investigative media outlets; stop-and-frisk policing strategies against minorities; wholesale deportation policies; and many other noxious ideas. He has deliberately coarsened America’s political language – systematically humiliating opponents and bringing his crowds down with him into the political sewers in which he thrives. His project is that of the classic totalitarian: make everyone and every major institution of state so grubby, so complicit, that, over time, they come to feel that they have no choice but to collaborate with an agenda of oppression.

We know that powerful countries don’t work well when nuance is cast overboard. Totalitarian projects garner support until they throw entire populations into disaster – into economic calamity, into spiralling conflicts and wars, into civil strife. Trump, as he makes policy on the hoof and hires a cabinet that seems to be made up of equal parts fanatics, conspiracy theorists, incompetents and generals, shows no sign of understanding this. He is a leader without internal limits.

Using his Twitter platform, in particular, Trump spent the weeks between election day and his inauguration wielding a wrecking ball against everything from environmental policy to gender equality regulations; from the “one China” policy carefully respected by leaders of both parties for more than 40 years to policies against expanded Israeli settlements in the occupied territories. Three days before Christmas, he suggested that the US would be expanding its nuclear arsenal under his leadership.

This isn’t just dangerous; it’s beyond idiotic – a man who will soon wield unholy power over the lives of everyone on this planet intervening in the most delicate of policy areas with the bluntest of cudgels. The idea of making nuclear policy through 140-character tweets is insane, the stuff of bad late-night comedy rather than serious international diplomacy. And yet, intellectually, this is where America’s incoming leadership now resides.

Trump’s actions over these past weeks indicate that he is a person of staggering hubris, of thoughtlessness, of impulsiveness – and that, as he presented himself time and again during the election season, he is a boy-man, with the sensibilities of a teenager rather than a mature adult. He comes across as someone megalomaniacally confident that he can think and do no wrong; who wants to listen only to sycophants; and who is convinced that his brand of instinctual politics (the kind that has no need for dreary, real-world interventions such as daily security briefings) will triumph over all.

On the night of the election, the New Yorker editor, David Remnick, wrote an impassioned essay about what he identified as an “American tragedy”. But this doesn’t do full justice to the catastrophe that Trump’s election represents. His is a triumph of the will, as surely as was Hitler’s rise to power in 1932-33. He has ridden and will continue to try to ride roughshod over his opponents – both within the craven GOP, which has sacrificed all semblance of democratic credibility in pursuit of power, and in the Democratic Party and beyond.

Because he enters the White House as a conqueror rather than a product of years of politicking within the existing governing structures, he knows that he can appeal to “the people” – not all of the people but those white, conservative, mainly rural and suburban residents who make up the core of his support – to get his way.

Will Trump succeed in this mad re-imagining of what the United States is? There will be large opposition – on the streets, on university campuses, in the courts and in the state houses of liberal states up and down both coasts. In wealthy and large states such as California, where the cities, state legislatures and the governor’s offices are united in opposition to huge parts of Trump’s agenda, it is likely that on a day-to-day basis residents will avoid the brunt of the impact.

It is entirely possible that there will be a flowering of radical politics in cities such as Los Angeles, San Francisco, Portland, Seattle, New York and Boston, as well as inward migration from the heartlands of large numbers of political progressives and members of racial and religious minorities. Yet in more conservative parts of the country – in Texas, say, or Oklahoma, Mississippi or Alabama, or a host of other states dominated by reactionary political leaders – life for immigrants, the working poor, single mothers and Muslims (just to take a few examples) will become harsher. In many states, it is not at all clear that the political leadership will be willing or able to stand up to Trump’s mob.

It’s also far from certain that local police forces or county sheriffs will be able, or even particularly inclined, to stop the unleashing of pogroms. After all, these are places where law enforcement long turned a blind eye to lynch mobs directed against black residents and black-run businesses. It is not such a stretch to imagine a similar passivity in the face of anti-Muslim or anti-Mexican violence today.

Nor, on the international stage, is it likely that this troupe of political novices will be able to control the forces of resentment they are unleashing. Trump’s cabinet is full of Islamophobes who believe that the entire Muslim world is now America’s enemy. It is dominated by China-haters and climate change deniers. By the time Trump assumes the presidency, he will have done an almighty job of pissing off swaths of the world’s population.

The optimistic scenario is that the world turns its back on an inward-looking America, getting on with the serious business of international affairs while the pre-eminent superpower throws a four-to-eight-year tantrum. It is more likely, however, that there will be a scramble for influence as US soft power wanes and other powerful countries and non-state organisations seek to fill a vacuum created by the dearth of sensible American voices and policies. Such players could range from economic powerhouses such as China and Germany, seeking, or being forced to accept, a bigger military and geopolitical role, to resurgent powers such as Russia – as well as non-state actors ranging from terrorist entities such as Isis to techno-anarchist groups such as WikiLeaks.

As America’s image mutates, they will have a growing opportunity either to sow instability or to reshape regions of the world in their own image. The nightmare scenario is that Trump, relying on his instincts in place of the counsel of experts, seeks to shore up America’s declining influence through spasmodic demonstrations of military power – bullying and threatening one country after another, much as fascist regimes did in the 1930s. The consequences could be disastrous: US nationalism unleashed could plunge the world into conflict.

Thus we hover on the edge of a catastrophe: a great democracy that has come to be controlled by demagogues, ready to pounce at the slightest provocation, itching for an excuse to implement emergency measures against Muslims and others, convinced that its military might will cow the rest of the world into toeing the Trumpian line.

Sasha Abramsky writes for the Nation magazine and is the author of “The American Way of Poverty” (Nation Books)