Watching today’s inauguration of Joe Biden as the United States’ 46th president, there’s not a lot in common with the inauguration of Donald Trump just four destructive years ago. Where Trump warned of carnage, Biden dared to hope for unity and decency. But the one place they converge is that both inaugurations ask the American people this central question: How far?

Biden’s sunny inauguration ceremony today speaks to just how much work there is to do to repair the damage done by the self-interest and fear-mongering of his predecessor. Biden took his oath of office in a Washington DC swarming with troops after the raid on the Capitol Building. With a tiny, masked crowd, because of America’s inept handling of Covid-19 pandemic thus far. As he said, “there is much to repair, much to restore”.

But how far will Americans let him go down his chosen path? America’s political pendulum has swung. But how far?

The question was the same one facing Trump in 2017. Americans had voted for a populist nationalist, the ultimate outsider and showman, a bully and a narcissist. Scared of rapid social change, wanting a return to an America they were more familiar with, indulging racism and sexism, relying too heavily on the manipulated ‘news’ of social media, looking for strength and security in uncertain times, seeking a return to conservative values (especially on abortion) and increasingly fed up with the failings of the political establishment, a coalition of frustrated Americans voted for a man demonstrably unfit for the job.

So the question was how far would they indulge him to get what they wanted? Because Trump has always been the symptom, not the cause. How far would they allow him to go?

The answer over the past four years is farther than most of the world hoped or expected. The lie of inauguration size was trivial on its own, but on the first day of his presidency is set the tone. Or rather, it showed the tone of his candidacy - with the Obama birther lie, the mocking of a disabled reporter, the release of tapes showing a history of sexual abuse - would continue into office. And so it turned out, leading to not one, but two impeachments. The court cases are still to come.

In truth, and contrary to some hyperbole, Americans have kept him on a short leash whenever they have had the chance. In the mid-terms he suffered a series of defeats and lost the House. He now leaves office a one-term president, having lost the popular vote in every election in which he stood.

Biden in just his first day will undo - or start to undo - some of Trump’s most anti-institutionalist damage. He will reverse America’s withdrawal from the World Health Organisation, repeal the ban on immigrants from some majority-Muslim countries, and get his country back into the Paris climate change agreement.

In many significant, but short-term ways there’s no doubt we will see a pendulum swing back towards institutionalism and decency. Less appealingly, there will also likely be a swing back to American triumphalism and arrogance.

But the big question for me is if this is a pendulum swing for history. Or is Biden going to be a blip in the decay of American democracy?

America’s loss of faith in its democracy and its political servants can be traced back to Richard Nixon. You could argue it’s bigger than him and Watergate, pointing to the Vietnam War and a raft of social upheaval since World War II. But with the exception of George HW Bush, every president since Nixon has been a pendulum swing in one direction - away from the establishment and towards the ‘outsider’.

From a peanut farmer from Georgia through to a reality TV businessman from New York, American’s have gone further and further to the extreme looking for someone to fix Washington and get its politicians to listen and act in the public interest. Ronald Reagan was a movie star. Bill Clinton a young, boomer change of the generational guard. George W Bush was the guy you’d want to have at your BBQ and ran as an outsider from Texas even though he was from an establishment family. Barack Obama was a young black man, also kicking against the established order. Each time voters told their leaders they were prepared to go further and further from the mainstream, to try a different approach, in the quest for the kind of America they want.

Trump was the natural, illogical extreme end of that search.

So Joe Biden represents the first swing back to the establishment since at least GHW Bush and - taking our his blip of a single term - since Nixon right back in the 1960s. That’s nine presidents ago.

So does his election show that enough Americans have reconnected with the importance of someone who respects the institutions of democracy, who knows how ‘the swamp’ works and who has expertise in the realm of government? Is this a recognition that outsiders can seldom deliver on their promises? And a move back to an old style of leadership?

Or is this just America catching its brief before another style of outsider comes along? Does the US want to protect and incrementally evolve what it already had - for better or worse - or is it still “restless” as Biden says, looking for a bolder, brasher solution?

The answer will in part rest heavy on Biden’s shoulders? Can he deliver some sense of security and hope to the white middle and working classes, while also drawing in so many groups who have been left out of the American dream for so long? In his speech he promised to both “restore” and “start afresh”. That’s a tough ask. And, perhaps sadly, he is likely to be a one-term president, which makes the tasks even harder.

Perhaps it gives him urgency. But perhaps it’s not enough time. We’ll see.

For today, Biden is offering the key message of unity. He leant heavily on the word in his speech and it looks to be at the core of his vision for the next four years. The question remains, how far has the pendulum swung and how far will the people let him bring them together.