ou may not have noticed, because he is not nearly as in-your-face as his predecessor, but Joe Biden is currently teaching a lesson to left and centre-left parties around the world. True, it’s one they should have learned long ago, but still they should be paying the closest attention. Because Biden is delivering a masterclass. I’m not referring to his debut White House press conference on Thursday, in which he showed that, for all the tripping up on the steps to Air Force One or the supposed senior moments, his political instincts remain sharply intact. To cite just one illustrative moment, Biden was asked whether he would be running for re-election in 2024 and whether his opponent would be Donald Trump. He replied with a half-joke, saying he had no idea whether he’d face Trump, and indeed “no idea whether there’ll be a Republican party”, adding that he was “a respecter of fate” who had learned not to make plans for several years ahead. In that answer, he managed simultaneously to punch the bruise of his opponents’ current identity crisis, as Republicans ask themselves if they are anything more than the Donald Trump fan club, and to remind Americans of the sudden and cruel losses that have marred his life, and have given him an emotional gravitas unusual in politics. It was a deft response for a man easily mocked as clumsy on his feet. But it’s not Biden’s words – which, incidentally, have been counted along with his on-camera appearances and total one-third of those notched up by the previous president at the equivalent stage – so much as his actions that would-be progressives should be studying. Recall how Biden campaigned. He presented himself as a reassuring grandfather of the nation who would restore calm and decency to the US government, a steadying presence who believed in the old-fashioned virtue of quiet competence. He would not be exciting; he would not light up social media. When the right claimed he was a radical socialist, the charge did not stick – because Biden had been around for 50 years and people could see with their own eyes that he was a traditional moderate. That view was helpfully reinforced by those leftists who had long written Biden off as a dull, decrepit centrist, barely fit to shine the shoes of progressive favourites such as Bernie Sanders or Alexandria Ocasio-Cortez. But look at him now. Two-thirds into its first 100 days, and the Biden presidency has easily secured the right to be described as radical. Usually sober observers of the White House are going further: just two months after Biden took the oath, they are branding him a transformational president. The comparisons to Franklin D Roosevelt and Lyndon Johnson have already begun. And Biden is encouraging them. Earlier this month, he sat for two hours with a group of presidential historians, pressing them hard on how FDR and LBJ had moved swiftly to make changes so profound and systemic they endure to this day. At the Thursday press conference, Biden made explicit the scale of his ambition. “I want to change the paradigm,” he said, three times. What is the basis for such talk? The foundation stone is the $1.9tn Covid relief package Biden signed into law a fortnight ago, which has seen $1,400 payments land in the bank accounts of more than 100 million Americans. But this is about far more than a short-term stimulus effort. One estimate calculates that the move will, at a stroke, cut child poverty by half. The poorest 20% of families will see their income rise by 20%. The law expands subsidies for healthcare and introduces something akin to child benefit. It directs $4bn to black farmers, in what some have hailed as a first step towards reparations for slavery. If past is prologue, such measures once given are near impossible to take away. Not for nothing does the conservative columnist David Brooks call Biden’s Covid relief law “one of the most important pieces of legislation of our lifetimes”. This is why Biden’s invocation of a paradigm shift might not be overblown. He is overturning four decades of hostility to big government, replacing it with an expectation that if citizens are living economically precarious lives, if inequality is rampant, then it’s the job of the state to step in. In the 2008 presidential campaign, Republicans lambasted Biden and Barack Obama for wanting to “spread the wealth around”. Now, under Biden, the US government is engaged in a massive wealth redistribution programme – and the polls show Americans, including Republican voters, warmly approve. It doesn’t hurt that the president is simultaneously succeeding in his most vital task, turning around a Covid vaccination effort that had barely started under Trump. Biden promised to get 100m jabs into American arms in his first 100 days; in fact, he hit that milestone on his 58th day in office, and now aims to reach 200m shots by day 100. If he can get the pandemic under control and the economy on track, Biden is signalling that he’s ready to act big, and fast, in other spheres. In the pipeline is a green energy and infrastructure plan that, coupled with an education bill, carries an astonishing $3tn price tag. He’s also under pressure to fend off Republican voter suppression efforts, aimed chiefly at keeping black Americans away from the ballot box, by passing a voting rights act, and to make other democratic reforms, whether granting statehood to the District of Columbia and Puerto Rico or scrapping the filibuster mechanism – both of which would offset the inbuilt advantage the current system gives to America’s white, rural minority. These would be truly transformational acts, performed by a man who was seen, and in some quarters condemned a matter of months ago, as nothing more than a steady-as-we-go servant of the status quo. And yet that contrast is not a paradox. It’s a method. This is the first lesson that Biden is teaching would-be reformers. If you want to be radical in office, first reassure in opposition. If your goal is to win power, then in societies where people tend to be small-c conservative, your initial task is to persuade them that they have nothing to fear from you – that your concerns are their concerns. Remember Biden’s campaign: no gestures, no striking of radical poses, no indulgence of either. He was not campaigning to be a Twitter darling, nor to be president of the student union. He wanted to be president of the United States. And that’s the second key lesson from Biden, one as old as politics. The true radical is not the fiery deliverer of revolutionary speeches or writer of maximalist manifestos. The true radical is the one who wins power and uses it for good. Biden has achieved more in two months than those who like to trumpet their radicalism manage in a lifetime. And he’s done it because he understands something that eludes so many. He understands that the greatest hope is power. Jonathan Freedland is a Guardian columnist Join Jonathan Freedland and Guardian US journalists Richard Wolffe and Joan E Greve, for a Guardian Live event on the first 100 days of Joe Biden’s presidency. Wednesday 28 April, 7pm BST | 8pm CEST | 11am PDT | 2pm EDT. Book tickets here