Well, what were you expecting? Did you somehow think that the Donald Trump of the long, bitter campaign of 2016 would be miraculously transformed in the Washington rain, emerging as a kinder, gentler man, ready to serve as healer of the nation and humble steward of the free world? Because if you did, you were sorely disappointed.

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Of course he didn’t change. The naive thought he might shift a year ago, when he became the Republican frontrunner, or in the summer, when he became that party’s nominee, or in November, when he won the election. And some, finally, clung to the hope that he would “pivot”, undergoing a metamorphosis as he placed his hand on the Bible and took the oath to become America’s 45th president. But they were wrong.

The Trump on the steps of the Capitol was the same Trump the world has come to know and fear. As he did at his party convention in Cleveland, he came with a message full of anger and foreboding, slamming the record of his predecessor and depicting a bleak American dystopia. He spoke of “American carnage”, of gangs and drugs, crime and decay.

And he was unafraid of the darkest historical echoes. “From this day forward, it’s going to be only America first,” he said, “America first” – embracing once again the slogan of the 1930s nativist movement of appeasers and antisemites who sought to keep the US out of the war against Nazism. Elsewhere, in rhetoric that sounded chilling coming from a would-be strongman who allegedly used to keep a volume of Hitler’s speeches at his bedside, he declared, “We are one nation … We share one heart, one home, and one glorious destiny.”

For a listening world, there was little of comfort. He announced a new age of protectionism, not hiding from the word. “Protection will lead to great prosperity and strength,” he said, in defiance of the historical experience that says protection leads, in fact, to crisis and world war. There was no mention of Nato or anything that might smack of multilateral cooperation. Instead Trump used his inauguration to usher in a new, Darwinian era in international relations. From now on, “all nations [will] put their own interests first”. That’s how Moscow and Beijing see the world, but it’ll be a shock for those smaller nations who have long looked to the US to maintain something close to a rules-based international system.

In other words, Trump did what he always does: he shredded the rule book. Inaugural speeches are meant to be exercises in national unity, binding the wounds of a divided people and sending a message that might hearten the rest of the world. Not for Trump. There was no gracious nod to his defeated opponent, Hillary Clinton, no hand outstretched to those who didn’t vote for him.

Instead, he spoke to his own voters, doubling down on the message of economic nationalism that brought him those narrow margins in the key rust-belt states. He spoke of “rusted-out factories scattered like tombstones across the landscape”, the workers who had been “forgotten” and “left behind”, and promised they would be forgotten no more. For them this speech – and, indeed, slogans such as America first – would have been compelling. They will be readier than ever to believe that he is about to make good on his multiple, impossible promises – including the eradication of “radical Islamic terror” from the face of the Earth – as well his defining and closing pledge: to make America great again.

So what should those who have long dreaded this moment do now? For some, the inauguration marks the launch of what they’re already calling “the resistance”, as if they are facing not just an unloved government but a tyranny. Note the banner held aloft by one group of demonstrators that read simply: “Fascist.”

Placards and protests will have their place in the next four years. But those who want to stand in Trump’s way will need to do more than simply shake their fists. The work of opposition starts now – and here’s how it might work.

At the front of the queue, as it were, are the press. There’s no doubt Trump sees it that way. With Clinton out of the way, the media has become his enemy of choice. The media’s very existence seems to infuriate him. Perhaps because it’s now the only centre of power he doesn’t control. With the White House and Congress in Republican hands, and the casting vote on the supreme court an appointment that’s his to make, it’s no wonder the fourth estate rankles: he already controls the other three.

That puts a great burden of responsibility on the press. Trump has majorities in the House and Senate, so often it will fall to reporters to ask the tough questions and hold the president to account. And it won’t be easy, if only because war against Trump is necessarily a war on many fronts. Just keeping up with his egregious conflicts of interests could be a full-time job, to say nothing of his bizarre appointments, filling key jobs with those who are either unqualified or actively hostile to the mission of the departments they now head. It’s a genuine question whether the media has sufficient bandwidth to cope.

But one move could help. Journalists might need to break the competitive habits of a lifetime and, every now and then, work as a team. That need was illustrated in last week’s press conference, when Trump turned on, and refused to take a question from, a CNN reporter, branding the network purveyors of “fake news.” Had the other journalists present refused to ask questions of their own until their CNN colleague was allowed his moment, Trump would have had to give way. In a similar vein, reporters should get into the habit of following up their colleagues’ inquiries. It may not force Trump or his spokespersons to answer awkward questions, but at least it’ll make it a tad harder for them to ignore them.

But there’s also a question of focus, for the press and for opponents alike. It’ll be tempting to go after Trump for his late-night tweets, for the insults he will surely keep firing off – whether at Meryl Streep or the cast of Hamilton – and for the general boorishness that has made him so repellent to so many millions. Tempting, but if it’s allowed to dominate the way we speak about this president, wrong.

Listen to the advice of the Italian scholar Luigi Zingales, who recalls the long battles against Silvio Berlusconi – like Trump, a master player of the media, orange-hued and coated in a Teflon that meant no scandal ever stuck. Berlusconi was in the end defeated only by those who “focused on the issues, not on his character”. Attacking Trump as a douchebag might be cathartic, but it’s unlikely to be effective. Too many Americans knew that about him but voted for him anyway. Better to attack Trump as a president.

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Which is not to say that there’ll be no room for mockery. Lord knows, laughter will be a crucial weapon against Trump, as it is against all authoritarian strongmen.(Indeed, humour seems alien to Trump: comedy director Judd Apatow this week noted that he had never seen the new president laugh properly.) Alec Baldwin and Saturday Night Live, along with Trevor Noah, Samantha Bee and others are the bearers of a solemn, quasi-constitutional duty: to point a jeering finger at the emperor with no clothes.

But that will count for nothing if there is not a popular movement of dissent, one that exists in the real world beyond social media. Some believe the mass rally is about to matter more than ever. Trump, remember, is a man who gets his knowledge of the world from television, and who is obsessed by ratings. How better to convey to him the public mood of disapproval than by forcing him to see huge crowds on TV, comprised of people who reject him?

And this will have to be backed by serious, organised activism. The left can learn from the success of the Tea Party movement, which did so much to obstruct Barack Obama. That will force congressional Democrats to consider whether they too should learn from their Republican counterparts, thwarting Trump rather than enabling him.

And opponents should keep their eyes on the prize. Yesterday’s most poignant image was of the Obamas leaving the White House for the last time. Eight years ago, that was Bush and Cheney. One day, it will be Donald Trump. That moment will come. The task now is to ensure it comes sooner rather than later.