“With fear for our democracy, I dissent.” So wrote the supreme court justice Sonia Sotomayor in a minority opinion this week. She was far from alone in the view that, with Donald Trump threatening an “imperial presidency”, American democracy is at a moment of maximum peril.Millions are pinning their hopes on the Democratic party as the last wall of defence. Surely, they believed, Democrats would field their best and brightest led by a dynamic presidential candidate and demagogue slayer. Instead the party is offering 81-year-old Joe Biden and an internal civil war.Biden’s career-worst debate performance against Trump last month has triggered acrimony, angst and panic among Democrats just four months from election day. There are growing calls for oldest president in US history to step aside in favour of Vice-President Kamala Harris – or someone else. But Biden has so far dug in and vowed to fight on.It would be a hugely consequential decision for any party at any moment, but the one thing that Democrats agree on is the stakes are uniquely high. America’s highest court has shifted right, thanks to three Trump appointees, and could indulge his authoritarian impulses should he be elected. A Trump victory would also have dramatic implications for Ukraine and other US allies.“American democracy is facing a category 5 disaster here,” said Charlie Sykes, a conservative political commentator and Trump critic. “Not just the election but the court. Unfortunately the Democratic party feels like it’s paralysed and refusing to acknowledge reality.”Debate viewers were shocked because Democrats had created an alternate reality bubble, Sykes added. “It reminds me a little bit of what what the Republican bubble felt like a few years ago where people will say one thing in private but they won’t say it in public. In private people know that they have a real problem with Joe Biden, that it was a disaster, that it might not get better, but they’re unwilling to say that in public and right now that’s an untenable solution.”America celebrated its 248th birthday this week with its customary barbecues, fireworks and flag-waving, but its democracy has been ailing for some time. The Watergate scandal, which led to Richard Nixon’s resignation, and the Ronald Reagan era helped sow distrust in government, while the the 2008 financial crisis fuelled a sense that the system was failing to deliver.View image in fullscreenThe supreme court’s Citizens United decision in 2010 opened the floodgates for special interests to pour money into elections. Republicans have mounted voter suppression efforts. Gerrymandering, the process whereby a party redraws district boundaries for electoral advantage, has fuelled polarisation and often means the loudest and most extreme voices are rewarded in party primaries.Structural flaws have been brutally exposed. The Senate, where states have an equal voice irrespective of their population size, has become unrepresentative and calcified by procedural rules such as the filibuster. Republican presidential candidates have won the national popular vote only once in the past 36 years, yet both George W Bush and Trump gained the White House via the electoral college.That means five of the nine supreme court justices were appointed by a president who lost the popular vote. Trust in the court is now an all-time low. Along with corruption scandals, the justices have defied public opinion with decisions such as the overturning of Roe v Wade, a precedented that enshrined the constitutional right to abortion.In the past two weeks, the court’s rightwing majority delivered a big blow to the regulatory powers of federal agencies and ruled that officials can accept cash or gifts from people they have assisted: they only count as bribes if given before the favour. Then, most consequentially of all, came its decision to expand presidential power.In a 6-3 decision, the court said former presidents have absolute immunity from investigation or prosecution for official acts that fall within their core functions. They are also presumptively entitled to immunity for all official acts. They do not enjoy immunity for private actions.The ruling was a major victory for Trump, who stands accused of orchestrating the deadly January 2021 insurrection but will now almost certainly not face trial in Washington ahead of the election in November. Sentencing for Trump’s hush money convictions was also postponed until at least September as the judge agreed to weigh the possible impact of the decision.The dissenting opinion, written by Sotomayor, was scathing as she considered what a president can now do. “Orders the navy’s Seal Team 6 to assassinate a political rival? Immune. Organizes a military coup to hold on to power? Immune. Takes a bribe in exchange for a pardon? Immune. Immune, immune, immune … In every use of official power, the president is now a king above the law.”There was condemnation of the ruling across the political spectrum. Sykes, author of How the Right Lost Its Mind, warned: “The supreme court decision raises the stakes because just imagine unleashing an absolutely immune Donald Trump on the nation, knowing that he can break the law at least in some respects with impunity.“That to me is the breathtaking part of it. It’s not some abstract where you’re talking about Jimmy Carter or Bill Clinton or George HW Bush. It’s Donald fucking Trump that you are basically saying should be above the law.”Paul Begala, a scholar at the University of Virginia’s Center for Politics and former adviser to Bill Clinton, told the Guardian’s Politics Weekly America podcast: “We had a good run. We go back to June 15, 1215: your country creates the Magna Carta. So we had 809 years of believing that no king, no president was above the law and that’s come to an end.“I’m sorry to sound cynical about it but it’s that dire because we’re about to put that power, potentially, in the hands of someone who we know from past experience will blow through any guideline, regulation and now he’s been given carte blanche by the supreme court.”View image in fullscreenTrump, 78, who is running a vengance-driven campaign and has expressed admiration for strongmen, has already quipped that he would be dictator on “day one” as president. His agenda for a second term is more extreme than the first – and better organised. The cabinet, congress and courts are likely to be more loyal and compliant, with fewer guardrails in place and fewer dissenters mounting resistance.Informed by policy documents such as the conservative thinktank Heritage Foundation’s “Project 2025”, Trump has made no secret of his plans to purge the federal government of thousands of civil servants deemed disloyal, weaponise the justice department against perceived political foes, slap 10% tariffs on thousands of imported goods and open detention camps to deport millions of undocumented immigrants.skip past newsletter promotionafter newsletter promotionIn this context, Biden is carrying the weight of the world on his frail shoulders: the 2024 election is a must win. But his raspy-voiced debate performance in Atlanta – losing his train of thought, stumbling over words, failing to combat Trump’s lies – revived anxieties over his fitness of office. Having identified him as the right man at the right time for the pandemic election of 2020, Democrats are now tormented by the possibility that they chose the wrong candidate for 2024.Questions swirled over whether Biden’s inner circle had been concealing his weaknesses from public scrutiny for some time. Congresswoman Nancy Pelosi, 84, a former speaker of the House of Representatives, wondered on the MSNBC network: “Is this an episode, or is this a condition? It’s legitimate – of both candidates.”After huddling with advisers and family members, Biden acknowledged that he nearly “fell asleep on the stage” during his poor debate showing, blaming it on a cold and jetlag, even though he had returned from Europe 12 days earlier. He told an all-staff campaign call: “I am running. I’m the nominee of the Democratic party. No one’s pushing me out. I’m not leaving.”The Biden campaign dug in its heels and dismissed the critics as “bed-wetters”, a dismissive attitude that disgusted some senior Democrats and made the situation worse. There was also frustration that Biden waited several days to do direct damage control with senior members of his own party. Some said the response had been worse than the debate performance itself.Two Democratic members of Congress called for Biden to quit the race and discontent on Capitol Hill is said to run much deeper, with many Democrats fearing that Biden could also cost the party the House and Senate. A major Democratic donor, Netflix co-founder Reed Hastings, also called on the president to step aside.Norman Solomon, national director of RootsAction.org, sponsor of the Step Aside Joe! campaign, said: “The train wreck around the bend is clear if he’s still the nominee, if he’s still the candidate. There’s an emergency cord that can be pulled.”View image in fullscreenSolomon warned: “The last days have brought powerful signs that the threat to democracy has become greater than ever. It’s a one-two punch. The obvious, clear evidence that Biden isn’t up to the job either to defeat Trump or to be president if he were to be re-elected.“Then this supreme court decision and it all underscores that the rather solipsistic fixations of the top of the Biden clan jeopardise democracy in a way that is a dream for the extreme right wing in the United States. The Biden performance was a gift-wrapped present to the Maga Republicans. It was everything but unwrapping the bow and taking off the wrapping paper.”The latest polls are fuelling alarm. A New York Times / Siena College survey found Trump leading Biden 49% to 43% among likely voters nationally, a three-point swing toward the Republican from before the debate. A Wall Street Journal poll found that 80% of voters think Biden is too old to run for a second term. A survey by Our Revolution, a political organising group, found that two in three progressives want Biden to suspend his campaign.But time is short to make a change. The Democratic National Committee announced weeks ago that it would hold a virtual roll call for a formal nomination before the party’s national convention, which begins on 19 August. Harris is emerging as the favourite to replace Biden if he were to withdraw, although governors Gavin Newsom of California and Gretchen Whitmer of Michigan remain viable alternatives.A messy, divisive convention – where protests over the war in Gaza are already expected – would only reinforce the suspicion that, with American democracy hanging by a thread, the Democratic party is failing to meet the moment.Larry Jacobs, director of the Center for the Study of Politics and Governance at the University of Minnesota, said: “American democracy and the force of the conservative movement that we’re seeing in the supreme court lacks a coherent, energetic counterpoint. The Democratic party is simply not up for the fight. The conservatives are marching ahead and the Democrats are flailing.”Jacobs added: “It’s reasonable to ask, why did it come to this with regards to Biden? Why weren’t party leaders intervening a year and a half ago to to usher off Biden to bring in genuine competition? Instead they leave it for a debate which realistic leaders could anticipate how it was going to turn out.“The fact that Trump was lying and bullying was known going in and Biden seemed so incapable of responding and so surprised by it. It was a very powerful signal of his infirmity but also of the infirmity party in moving past him. Joe Biden almost certainly can’t win, and the party seems incapable of processing that and taking action.” More