Is democracy in America really on the brink of collapse? A lot of serious people appear to think so. Last week’s first anniversary of the Capitol Hill insurrection, viewed by Democrats as a coup attempt incited by Donald Trump, has sparked a torrent of nervous speculation that it could happen again before, during or after the 2024 presidential election – and that next time, the coup may succeed.

One unhappy fact underpins this alarming scenario: many, perhaps most, voters have lost trust in the democratic system that governs them. A majority of Republicans believe Trump’s “big lie” – that Joe Biden stole the 2020 election. Democrats cite elections in 2000 and 2016 when Al Gore and Hillary Clinton respectively won the popular vote but were denied the presidency. Each side accuses the other of fraud and bad faith.

A new USA Today/Suffolk University poll found eight in 10 Republicans, Democrats and independents are worried about the future of American democracy. But they disagree over the causes – and who’s to blame: 85% of Democrats call the Capitol Hill rioters “criminals”; two-thirds of Republicans believe “they went too far but had a point”.

“Only free and fair elections in which the loser abides by the result stand between each of us and life at the mercy of a despotic regime,” warns Harvard law professor Laurence Tribe. But increasingly, for today’s politicians, honourable defeat is a wholly foreign concept.

This chronic loss of institutional trust and credibility, also tainting a politicised, conservative-dominated supreme court, reflects a society more openly riven by longstanding cultural, racial and religious animosities – and one in which income, wealth and health inequalities are growing. These divisions are in turn wilfully exacerbated by rightwing broadcast and online media, bloggers and internet trolls.

A Republican party mostly in thrall to Trump’s lies, delusions and conspiracy theories is creating a world of “alternative facts”, says columnist Thomas Friedman. If they succeed in replacing truth, “America isn’t just in trouble. It is headed for what scientists call ‘an extinction-level event’”.

Jedediah Britton-Purdy, a Columbia law professor, is similarly apocalyptic. “One thing Democrats and Republicans share is the belief that, to save the country, the other side must not be allowed to win … Every election is an existential crisis,” he wrote.

“We should stop underestimating the threat facing the country,” a grim New York Times editorial thundered last week. “January 6 is not in the past; it is every day. It is regular citizens who threaten election officials, who ask ‘when can we use the guns?’, who vow to murder politicians who dare to vote their conscience. It is Republican lawmakers scrambling to make it harder for people to vote and subvert their will if they do. It is Trump who stokes the flames of conflict.” Democracy, it said, was in “grave danger”.

Systemic violence that overwhelms conventional politics may be near at hand. “We are closer to civil war than any of us would like to believe,” says Barbara Walter, a California politics professor.

No one is talking about a remake of the 1861-65 US civil war. Instead, as in Ukraine or Libya, an “open insurgency”, as defined by Walter, would probably involve (at least initially), disparate militias and their supporters pursuing forms of asymmetrical warfare – typically terrorist acts, bombings, assassinations, kidnappings. That said, worrying echoes of Confederate-era secessionism are once again heard in Texas and elsewhere.

When the warlike rhetoric of Charlottesville-style paramilitary white supremacists, the high nationwide incidence of gun ownership and, for example, worries about far-right cells within the US military are factored in, civil war scenarios do not appear so implausible.

“Only a spark is needed, one major domestic terrorist event that shifts the perception of the country,” analyst Stephen Marche wrote last week. Marche quotes a military history professor and Iraq war veteran, Col Peter Mansoor, who tells him: “It would not be like the first civil war, with armies manoeuvring on the battlefield. I think it would very much be a free-for-all, neighbour on neighbour, based on beliefs and skin colours and religion. And it would be horrific.”

So what is to be done?

Columbia’s Britton-Purdy says America’s democracy is failing because it is not democratic enough. Old saws about the “tyranny of the majority”, propagated by founding father James Madison, among others, are redundant. The electoral college, which can override the popular vote, should be abolished, the franchise widened, and constitutional amendments curbing money in politics, banning gerrymandering and enshrining abortion rights should be voted on by all, he argued.

Cynthia Miller-Idriss, author of Hate in the Homeland, says a key problem is the “mainstreaming of far-right extremism” during Trump’s presidency. She advocates large-scale investment to strengthen communities and improve media literacy and civic education. Friedman wants corporate America to cut off funding to Trump and anti-democratic Republicans. “Civil war is bad for business,” he wrote. Just look at Lebanon.

Senator Bernie Sanders says radical change is the only answer. “At a time when the demagogues want to divide us … we must build an unstoppable grassroots movement that helps create the kind of nation we know we can become,” he says. Yet many Americans, including moderate Democrats, find the progressive left’s “transformational” agenda deeply disturbing, exemplified by calls to defund the police.

Harvard’s Laurence Tribe and fellow lawyers say that for democracy and the rule of law to survive, there must be accountability. That requires, in addition to the congressional inquiry, “a robust criminal investigation” into all those responsible for 6 January – including Trump. In a tougher than usual speech marking the anniversary, Biden condemned “the former president’s web of lies” – but gave no hint of legal or other action to punish or restrain him.

What would Alexis de Tocqueville, author of the famous study, Democracy in America, make of the present-day US? The French aristocrat and political scientist travelled the country in 1831-2, talking to ordinary people about governance and citizenship. He concluded, broadly, that democracy was an unstoppable, levelling historical trend that would eventually conquer the world.

Until relatively recently, many in the west still held to that view. Now, with the rise of China and other powerful authoritarian, anti-democratic regimes, optimism is fading – and America, the global paradigm, is itself under the reactionary hammer. Has De Tocqueville’s dream been exploded?

Not yet. The epic struggle for America’s democratic soul is just getting started. For a watching world, the stakes are sky-high, too. Where would Britain, Europe and all the globe’s democracies, actual and aspiring, be without the flawed but inspiring US example, without the “arsenal of democracy” to justify, validate and fortify their political universe?

Best ask Xi Jinping, Vladimir Putin and other despots. They are betting the ranch on the failure of American democracy – and aim to profit greatly thereby.