On July 4, Americans celebrate the day in 1776 when they declared their independence from the tyrant across the Atlantic, a distant, mercurial figure, by turns feared as an autocrat and written off as a madman. Britons, however, are likely to be thinking less about King George III than about the upcoming visit to the UK of Donald Trump, and their hope that the UK government will issue its own declaration of independence from a reviled American president.

Organizers hope that July 13 will see the biggest protest against a foreign leader in the country’s history. The bar is set high given the hostile demonstrations that greeted George W. Bush when he came to London in November 2003, the year of the invasion of Iraq. But Trump, who likes to boast about the size of his crowds, will surely break Bush’s record.

If the past is any guide, I might be asked to play pundit on the odd BBC program, invited to talk about the state of what the British still quaintly, and unrequitedly, call “the special relationship.” Back in 2003, I clocked up an hour or two on radio and TV explaining that the raucous presence of protesters using unrepeatable language to urge Bush to head back home did not indicate a new surge of anti-Americanism in Britain. On the contrary, I argued, Brits still loved the US. They watched American movies, read American fiction, took American vacations. “This is not anti-Americanism,” I insisted. “This is merely anti-Bushism.”

I could try a similar line next week. I could say that British hostility to Trump is wide and deep, but that admiration and affection for the US remains intact. In my search for affirming evidence, I might go upmarket, noting that the last two winners of the Booker prize, Britain’s most prestigious literary garland, have been American novelists, or downmarket, citing the tabloid devotion to Meghan Markle, now remade as the Duchess of Sussex.

I could do all that, but an inner voice would nag at me, nonetheless. For I am no longer so sure that next week’s protests will be narrowly anti-Trump. There might be a broader disenchantment underway—a shift that, for me at least, is quite personal.

This month, it will be twenty years since the publication of my first book, a polemic titled Bring Home the Revolution: How Britain Can Live the American Dream. (The paperback acquired a different subtitle: The Case for a British Republic.) I wrote it as a young, returning foreign correspondent, back in London after four years as The Guardian’s reporter in Washington, D.C. It briefly became a political talking-point. A copy was spotted at Chequers, the country residence of the prime minister, then Tony Blair. It was on the holiday reading list of the then leader of the Conservative Party, William Hague. The nation’s best-selling tabloid, The Sun, devoted an editorial to it. (It appeared alongside a cartoon depicting the Queen apparently rattled by the book’s call for the abolition of the monarchy.)

The book’s central argument was that Britons, so ready to import the latest faddish technology or corporate jargon from the US, were missing the real treasure worthy of ferrying across the ocean. The daily reality of US political life might often be unappetizing, I argued, but the country’s founding ideal, especially as expressed in the US Constitution, remained a model worthy of admiration and emulation. Whether that be a true separation of powers, an elected head of state, popular sovereignty, devolution of power from the center, an explicit and absolute guarantee of free speech, a “creedal” national identity that allowed for the full integration of immigrants or a written constitution, the US system was bursting with democratic safeguards absent in Britain. My country was still saddled with semi-feudal arrangements: not just a monarchy, but a legislature whose upper house was unelected and stuffed with earls and viscounts who had literally inherited their place in parliament. All power was hoarded in Westminster, with Scotland, Wales, or Northern Ireland enjoying none of the autonomy that would be regarded as basic by Connecticut or Colorado.

What’s more, I wrote, for Britain to learn from the US Constitution would be an act of cultural repatriation. For America’s founding ideal was Britain’s lost inheritance. The framers of that document were either British, or of British parentage, or had grown up under British rule. They were self-consciously working from a British template, seeking to adapt and improve the only system they had ever really known. The book concluded by insisting that:

Britain did have a revolution. The trouble is, we had it in America. The Founding Fathers were English radicals, who took a revolution intended for us and shipped it across the Atlantic. With it they exported our rightful destiny. It is time to bring it back home.

The following months and years would prove bumpy for my thesis. The impeachment of Bill Clinton in 1998 over what was then seen as a minor affair—few see it that way now—prompted much mockery. “You talk about the American dream,” one radio interviewer said. “It’s all a bit of a nightmare now, isn’t it?” The deadlock in Florida two years later, which exposed the eccentricities of the Electoral College system, set off another round of skepticism, not to say smugness, from outsiders’ assessing the merits of the US political system.

And yet, those critiques did not shake me too badly. In the Clinton case, I could reply that the system was working as it should, that the checks and balances were kicking in: the president was not, after all, removed from office and the voters had had their say, siding with Clinton by electing more Democrats to the House and Senate in the midterms of 1998. As for the Electoral College, sure, it was quirky, but victory for a popular-vote loser was clearly a once-in-a-century exception to an otherwise acceptable rule.

For several years, I continued in that vein. There would be a hideous school shooting and I would deplore it, before adding that there was nothing in the Second Amendment that actually required Americans to make military-grade weapons as easily available as fries and a shake. The power to halt gun violence was in Americans’ own hands. They could, through the Supreme Court, narrow the amendment’s scope, following the wisdom of former Chief Justice Warren E. Burger, who believed the amendment had “been the subject of one of the greatest pieces of fraud, I repeat the word ‘fraud,’ on the American public”—in that the Constitution had clearly meant to bestow the right to bear arms on states rather than on individuals. Or Americans could simply repeal the amendment, if that’s what the democratic will demanded. Either way, the Constitution could not be condemned as the source of America’s ailments. On the contrary, it contained their remedy.

And if that logic applied to one of America’s twin birth defects, guns, it surely also applied to the other: racism. True, the Constitution had enabled, first, slavery and, then, Jim Crow. But it had also, through the equal protection clause, made the civil rights revolution possible. In the Obama era, discrimination and prejudice persisted, of course, not least in the criminal justice system. Still, Supreme Court rulings in favor of affirmative action and equal marriage suggested that my faith in the Constitution’s ability to protect minorities remained sound.

Now, though, it is being shaken to its foundations. We’ve seen hideous US presidencies before, but what is happening under Trump goes further. The travel ban on Muslims and the separation of migrant children from their parents are disgusting in themselves, but they point to something larger than the ugly policy decisions of a specific administration that will, eventually, be gone. They suggest a fundamental weakness in the US system itself, one that I now fear I overlooked.

The flaw is that, for all of its talk of checks and balances—restraints that the US seemed to have formalized and entrenched more robustly than Britain—the American system does, after all, allow for unified, centralized, and unchecked government with, at its apex, an executive authority, the president, able to exercise untrammeled power. It was a British Conservative politician, Quintin Hogg, who once described Britain’s excessive concentration of power in the hands of the prime minister as an “elective dictatorship,” but that phrase now looks apt for a US president armed with pliant majorities in Congress and on the Supreme Court.

So no one can claim to be surprised by a President Trump who, to give just three examples, refuses to divest himself of business interests affected by his conduct of US foreign policy, appoints unqualified family members to senior posts, and demands the jailing of his political opponents. But they can justifiably be surprised by the failure of US institutions to restrain him on even one of those counts. (The last of the three is perhaps the most serious, even if the demand has not, so far, been acted upon: for the head of the executive branch to urge the prosecution of named individuals poses a direct threat to the rule of law.)

As early as 1796, George Washington was warning in his farewell address “in the most solemn manner against the baneful effects of the spirit of party.” Party allegiance has been a feature of the republic from the start. But the intense hyper-partisanship of today, in which Republicans and Democrats more closely resemble two distinct tribes—with their own, separate information systems, their own facts, even their own epistemologies—would surely have jolted America’s Founders. They designed a system as carefully calibrated and weighted as an antique clock, full of intricate checks and balances that once seemed timeless in their ability to generate political equilibrium. If one branch got out of out hand, the other two would hold it back. But for that elaborate mechanism to function fully, representatives, senators, or judges would have to act as something greater than party hacks. Conscience and the national interest would have to play a part, too. Without that, the system does not work.

For what use is the power of impeachment if the House is so stuffed with compliant members of the president’s party that it refuses to pull the lever granted to it by the Constitution, even when evidence of high crimes is abundant? What value has the Supreme Court if it, too, now breaks along partisan lines, with “Republican” justices using their majority to uphold even crude gerrymandering or voter suppression in states, apparently for no better reason than that those violations favor their side?

When I was a US correspondent, the Watergate scandal still lived strong in the memory; it had unspooled little more than two decades earlier. That also, in its own way, was an advertisement for the US system. Once the evidence against a Republican president became overwhelming, even Republicans in Congress turned against him. But if Watergate happened now, would it be Watergate? Or would the talking heads on Fox News and their congressional Republican echoes simply join the president in declaring it all to be fake news?

It now seems plausible that Special Counsel Robert Mueller could reveal the most damning case possible against Trump, there’d be a lot of noise for a few days, then some new outrage would explode for the media to talk about—and Trump would stay comfortably in his post. When Trump joked that he could shoot someone on Fifth Avenue and his backers would stick with him anyway, he was referring to his most loyal voters. Now we have good grounds to suspect that the same would be true of the supposedly co-equal branches of government, those whose duty is to resist such barbarism.

In other words, what the Trump presidency has confirmed is something I overlooked in 1998: that the Constitution may boast endlessly ingenious powers, but they count for nothing if the men and women charged with deploying those powers refuse to do their duty.

A similar oversight of mine relates to norms. Two decades ago, I loudly admired the American penchant for writing things down rather than relying on nebulous, unwritten conventions (which is the British way). US citizens could point to their liberties and protections spelled out in black and white in the Constitution and the Bill of Rights, while Britons relied on a haze of custom, interpreted by a select priesthood of experts, usually lawyers, scholars, or superannuated politicians, called upon to explain to the public the invisible rules of the game.

And yet, I see now that the US, too, has relied on a raft of norms and taboos to secure its liberal democracy. It might be the demand that candidates release their tax returns, or the parliamentary etiquette that used to insist that a president’s nominee for the Supreme Court at least get a hearing, but those customs have been shattered by a Republican Party willing to smash every convention that stands in its way. Today’s Republican Party, like its president, is utterly unfettered by the constraining power of shame. The result is that conventions once deemed immovable have been exposed as far weaker than we understood—not worth the paper they weren’t written on.

When Bring Home the Revolution was published, several critics took me to task for underplaying America’s deepest flaws, from the influence of money in politics to the centuries-old malignancy of white supremacism. I was not blind to those failings. But I believed that the Constitution, and the ideal it represented, were strong enough to provide answers to them—whether by protecting free speech or safeguarding the rights of minorities. In the era of Citizens United and Charlottesville, and—thanks to Senator Mitch McConnell and Justice Anthony Kennedy—facing the prospect of a solid Trump majority on the Supreme Court that could hold for four decades to come, that position is becoming ever harder to sustain.

Lord knows, Britain has great democratic ills of its own, now on display through the national exercise in self-harm that is Brexit. And America—in its creativity, its people, its restless genius—is still a magnetic presence in the world. But for those of us who once saw the US as a shining city on a hill, the light is dimming.