Left, right, Harris, Trump: all prisoners of political nostalgia in an era few understand | Rafael Behr

Donald Trump’s record of refusal to concede defeat after the last US election should have disqualified him from running in this one. His criminal indictments should have meant banishment from mainstream politics. His campaign rhetoric – a rambling litany of bigotry and spite – should not have carried beyond the paranoid fringe.

But what use are should and shouldn’t against the brute force of can and does? Things that are supposed to be self-evident in a constitutional democracy have ceased to be obvious to millions of Americans. We don’t need to wait for all votes to be counted to wish for a stronger cultural inoculation against tyranny.

A healthier body politic would not have been infected by Trump’s candidacy. How did the democratic immune system fail? He is gifted with a malign kind of charisma, but it needed a confluence of economic stagnation, cultural polarisation and technological revolution over many years to achieve maximum contagion.

There is always a risk of romanticising the past when coping with anxiety in the present. Aggressive nationalism that bristles with racism, misogyny and swaggering machismo is an old style in American politics. There is also nothing especially new in polarised social attitudes. Culture wars have been waged with varying degrees of intensity for generations.

What stands out as a uniquely 21st-century innovation is the segregation of political tribes into discrete and self-reinforcing information silos. Formerly, even in times of fierce political division, there were institutions and rules that governed debate. There were commonly agreed facts that might be subject to rival interpretation while still connecting partisans of opposite views to a shared reality.

That way of conducting politics is not obsolete, but it is rooted in analogue systems. It relies on real-life interactions, deliberations, clunky old institutions, meandering conversations, small talk. It is the stuff of people mingling in assemblies and town halls, breaking bread together. It is the opposite of politics played in digital mode where the platforms on which debate is conducted are also engines of radicalisation; where differences of opinion are accelerated into irreconcilable enmities.

This isn’t an elegy for some pre-internet golden age of enlightened public discourse. Prejudice, misinformation, sheer stupidity and abuse of power were abundant enough when information flows were tightly controlled and volumes were a tiny fraction of what they are now.

An apparent correlation between extreme politics and the rise of social media doesn’t prove a causal link. But there is a plausible argument that a very online culture, marked by short attention spans, narcissism and impatient consumer appetites, has a more natural affinity with shallow demagoguery than with representative democracy.

The whole apparatus of voting for a candidate who might not satisfy your exact needs, and probably doesn’t embody all the values you hold sacred, but might at least make some half-decent decisions for the country as a whole over the coming years, feels oddly antiquated. It is alien to the click-and-collect spirit of digital commerce.

A democratic election is the antithesis of an internet transaction. It contains not just an expectation of delayed gratification, but a guarantee of frustration. Compromise, imperfection and disappointment are the necessary price for having a government that tries to balance the complex demands of a variegated society.

The alternative is a political movement, such as the Maga cult, that treats elections as a cry of rage or exultant self-actualisation. Trump’s campaign has never construed voting in terms of civic choice, with more than one potentially legitimate outcome. It was always going to be either a heroic restoration of the rightful president or another iteration of the deep-state conspiracy against him. There is no place for defeat in the script except as material to bolster the claim of a higher victory.

It is a mode of campaigning that is hostile to the basic premise of a democratic ballot, which is that either side might win and counting votes actually counts.

It also exploits a culture of political journalism that measures professional integrity by a refusal to pick sides. It has been peculiar to observe liberal American media continuing to apply their conventional reporting templates, which contain the implicit judgment that the two candidates have equivalent democratic credentials. That is absurd when one of them transparently despises democracy.

Much of America’s moderate conservative and liberal establishment seems to have spent the campaign going through the motions of political normalcy, hoping to stir the system into resilience by operation of muscle memory. It doesn’t work.

But ringing the alarm at the spectre of fascism doesn’t work either. There is no doubt that Trump’s temperament and ambitions are fascistic. He admires dictators, lusts after absolute power, speaks of political critics as enemies and boasts of his willingness to crush them with armed organs of the state.

And yet calling that kind of politics by its proper name doesn’t provoke any scruple among his supporters. Partly that is because the currency of comparison with 20th-century dictators has been dulled by overuse. “Fascist” is a label that has been applied too casually and too often as unthinking abuse to be rehabilitated as a tool with moral precision and rhetorical impact more than 100 years after it was coined.

That doesn’t mean the lessons of the 1920s and 1930s are irrelevant to the current predicament. It is easy to find disturbing parallels, and the connection can’t be ignored when white supremacists and card-carrying neo-Nazis are an active cadre in the new radical-right coalition.

But there is also a danger for liberal opinion in leaning too heavily on the familiar cautionary tales from history.

Casting the threat as a resurgence of something old – a zombie ideology risen from its postwar grave – preserves the convenient idea of liberal democracy as the more modern and more highly evolved political system. It is the instinct to dismiss nationalism as an ideological retirement home for angry white people whose skills don’t equip them to compete in a dynamic, globalised economy, and who express their frustration as bigoted reaction against progressive social change.

There might be a dose of truth in that analysis – but it doesn’t contain an argument in favour of liberal democracy, beyond the implication that only stupid, bad people oppose it. Unsurprisingly, those same people don’t find that argument very persuasive.

The awkward truth for those of us who rally in defence of liberal democracy today is that it has undergone no obvious renewal since its peak at the end of the last century. We, no less than the nationalists, are imprisoned by nostalgia, wishing the future could be more like the past. And so we find ourselves constantly testing the limits of analogue protection against a virus that is digitally borne.

• Rafael Behr is a Guardian columnist