They thought it couldn’t happen here. But so did many other nations before America.

Walking the halls of the snowbound US Capitol on Thursday afternoon, a year to the hour since it was breached by a fascist impulse, it was hard to imagine the mob running riot – pummeling police, flaunting the Confederate flag and abusing a Black officer with the n-word.

But yes, it did happen here.

The cathedral of American democracy was scarcely attended and hauntingly hushed for the anniversary, in part because the coronavirus is rampant in Washington. Walk up a staircase and you might see a solitary reporter fetching coffee. Turn down a marbled corridor and you might spot a lone Capitol police officer – was he among those that fought and bled that day?

Republicans were particularly hard to find, their absence illustrating the radically different interpretations of what happened on 6 January 2021, or as one headline put it, “a national day of infamy, half remembered”. It was clear that America could not decide whether this was a political scrap or a national tragedy, a moment for angry polarisation or unified mourning. It did not feel like catharsis.

The vice-president, Kamala Harris, kicked it off just after 9am by pointing to “dates that occupy not only a place on our calendars, but a place in our collective memory”, citing 7 December 1941, 11 September 2001 – and 6 January 2021.

But whereas the Japanese attack on Pearl Harbor brought Americans together to fight the second world war, and the terrorist strikes on New York and Washington conjured rare solidarity, the deadly siege of the Capitol turns out to be just another wedge in the divided states of America.

And unlike those previous calamities, the more than 220-year-old Capitol bears few visible scars of the day that windows were smashed, congressional offices ransacked and faeces left on the floor. Without a tangible reminder, it is easier to deny reality or forget. Instead, the scars are psychological and institutional; the bleeding is internal.

Harris was followed by Joe Biden, whose barnstorming speech offered his most vivid critique yet of his predecessor Donald Trump’s big lie about the 2020 election and incitement of the mob. It was an I-don’t-negotiate-with-terrorists epiphany for the president about the limits of bipartisanship.

“I did not seek this fight brought to this Capitol one year ago today, but I will not shrink from it either,” said Biden, unexpectedly at 79 discovering his inner Henry V and previewing his 2024 election campaign. “I will stand in this breach. I will defend this nation. And I will allow no one to place a dagger at the throat of our democracy.”

But it was the details of that day – the sound of gunfire, the narrow escapes, the messages to loved ones – that struck a chord and stuck. They were bulwarks against the attempts to rewrite history and supplant it with a false narrative.

These details were recalled by senators speaking in the chamber that had been overrun by the rioters such as Jacob Chansley who, wearing a Viking hat and carrying a six-foot spear, scaled the dais and took the seat that Mike Pence had occupied an hour earlier, proclaiming, “Mike Pence is a fucking traitor” and writing, “It’s Only A Matter of Time. Justice Is Coming!”

There was Chuck Schumer, the Senate majority leader, who had only been in the chamber for 45 minutes, watching the start of the counting of ballots, when an armed police officer in a big flak jacket grabbed him firmly by the collar.”I’ll never forget that grip.” he said. “And said to me, ‘Senator, we got to get out of here, you’re in danger.’”

Schumer was within 30ft of “these nasty, racist, bigoted insurrectionists”, he recounted. “Had someone had a gun, had two of them blocked off the door, who knows what would have happened. I was told later that one of them reportedly said, ‘There’s the big Jew. Let’s get him’. Bigotry against one is bigotry against all.”

Senator Amy Klobuchar also had indelible memories of being evacuated from the chamber. “I remember the words of one staff member who yelled out, ‘Take the boxes. Take the boxes.’ She was talking about the mahogany boxes that were filled with the electoral ballots, because we knew they would be destroyed if they were left behind.”

She remembered how her staff hid in a closet with only forks to protect themselves, next to the doors where the insurrectionists had invaded. She remembered the cuts on the faces of police officers. And she remembered officer Harry Dunn, who was called the n-word multiple times, looked at his friend as they collapsed in the rotunda and asked, “Is this America? Is this America?”

Over in the House of Representatives, where 20 members had to take cover in the gallery that day, Speaker Nancy Pelosi presided over a moment of silence. Tellingly, there were only two Republicans on the floor: the former vice-president Dick Cheney and his daughter, congresswoman Liz Cheney, dying embers of the party’s anti-Trump resistance.

Dick Cheney said in a statement that he is “deeply disappointed at the failure of many members of my party to recognize the grave nature of the January 6 attacks and the ongoing threat to our nation.”

That failure was manifest in the decision of Republican leaders Mitch McConnell and Kevin McCarthy to stay well away from Washington. Minority whip Steve Scalise’s office did have a sign that said, “Thank you, U. S. Capitol police heroes”, but it opened to reveal a staffer and a TV showing replays of the riot, but no sign of the congressman himself.

Trump had cancelled a press conference but there were two Republicans who could not resist the limelight. In a tiny room (for which they inevitably blamed Pelosi), Trump acolytes Matt Gaetz and Marjorie Taylor Greene spun baseless conspiracy theories about FBI involvement in the deadly attack. Gaetz insisted: “We did not want the Republican voice to go unheard today.”

Greene played the all too familiar whataboutism card. Don’t forget, she said, that Senator Bernie Sanders thinks the 2016 Democratic primary was stolen from him, and Hillary Clinton thinks the 2016 general election was stolen from her. “If Democrats cared about riots, they would have cared about the Antifa-BLM riots all over the country in 2020.”

When one reporter challenged Gaetz about Biden’s memorable image of a dagger being held at the throat of democracy, the Florida congressman insisted: “We are here to vindicate our democracy.”

That is the twist: the mass delusion behind Trump’s big lie is that his followers believe they are saving democracy rather than destroying it. Republicans are imposing voter restriction laws and seeking to put Trump loyalists in charge of running elections. The next assault on the republic is unlikely to be as clumsy or crude as 6 January.

Thursday’s commemorations ended with a prayer vigil on the US Capitol steps. Two decades ago on 9/11, Democrats and Republicans stood side by side here and sang “God Bless America”. This time, holding candles and wearing masks as the US marine band played, Democrats again stood and sang “God Bless America”. This time, there were no Republicans.