Right now in the US, a lot of very powerful and rich people are having to confront a question that not long ago would have seemed impossible: what might happen if Bernie Sanders won the election? What would it mean if a self-proclaimed socialist were the 46th president of the United States of America?

Sanders won impressive victories in early nomination contests, his support concentrated among young workers –women and men of all racial backgrounds. Even in South Carolina, a stronghold of right-wing Democratic machine politics that went heavily in Joe Biden’s favour, Sanders won over 15 percent of the vote, and some pro-Sanders delegates were elected to the nominating convention. That feat was not achieved by establishment candidates like the former naval intelligence officer Pete Buttigieg, or the two candidates that, like the Iraq War, were endorsed and promoted by the New York Times: Elizabeth Warren and Amy Klobuchar.

Sanders’ impressive run has been achieved without any corporate backing. Far from it: big capitalists are overwhelmingly trying to destroy his candidacy, and one of them, Mike Bloomberg, is running directly against him for the nomination.

It’s enough to reduce some of the US’s political elites to a state of abject panic. Chris Matthews, one of the most prominent blowhards of MSNBC, famously worried that he might soon be publicly executed in Central Park before a baying mob of Bernie bros.

What are they so afraid of? As Sanders himself says, his proposals are not particularly radical, in the sense that they do not threaten the basic structures of capitalism. When it comes to things like a higher minimum wage, some kind of guaranteed access to health care, or more extensive trade union rights, many of his policies are in place, in one form or another, in many countries around the world. Campaign materials circulated by the Sanders team point out that health insurance is guaranteed in countries from Chile to Israel – the former a place where extreme inequality last year triggered a mass uprising, and the latter one of the world’s most notorious colonial occupying powers.

But the global capitalist class are not inclined to compromise when they can destroy. They think it’s their right to rule the world. Their go-to political strategy is sheer aggression. The ruling class has done pretty well in the decade since the global economic crisis by refusing to grant any concessions in the face of widespread hostility to the injustices of the status quo.

Since the financial crisis of 2008, capitalists have used their control of the economy, the media and the political process to destroy multiple reforming centre-left governments and major party candidates, from the Greek anti-austerity party Syriza – which was made to impose the harshest austerity that country had yet seen, until its voters became disgusted and it was turfed out of office – to Britain’s Jeremy Corbyn, who spent his last two years as Labour leader compromising over and over until he was badly defeated in an election and announced his resignation. The last few years have proven that the ruling class want to humiliate and destroy anyone who initiates a political project they find inconvenient.

And US capitalists, its high state officials and its news media aren’t just one more set of rich people. They’re the ruling class of what is still the world’s dominant military and economic power. For decades, they’ve been responsible for crushing democratic movements around the world. They have the strongest track record of supporting the most extreme measures – including fascist coups, like the one they endorsed in Bolivia last year. They’re hardly going to let even mild reforms take place at home – like a rolling back of the bloated, evil private health insurance industry – without a big fight.

That means Sanders still has plenty of obstacles between him and the presidency, especially as he’s running for the nomination of a party that is mostly a coalition of big business, senior US state officials and the craven NGOs and bureaucracies that serve them.

Even many who might sincerely wish the party were less terrible are heavily influenced by the basic logic of the US two-party system: candidates must be right-wing in order to win over capitalists and right-wing voters.

If Sanders can’t win an outright majority, it’s quite possible that the party apparatus will conspire to impose one of his defeated rivals. That would reflect not just the overwhelming hostility of the thoroughly capitalist Democratic establishment, but also the limitations of campaigning against that establishment to an audience that that establishment has cultivated.

Corporate money is flowing to his rivals. The baseline world view of many Democrat establishment figures and their supporters in the broader party base sees Sanders as an extremist who is similar to Trump in the ways that matter. The media are hostile, and the structures of the party favour the right. Those things may be enough to force Sanders into a minority and hand victory to one of his rivals.

But that’s not quite guaranteed. The media, and the bureaucracies that are subordinated to the Democrats, are not totally able to control public opinion. It’s variable: traditional politics prevailed in South Carolina, with African American voters overwhelmingly supporting Biden; but in Nevada, union members defied the right-wing instructions of the bureaucrats of the Culinary Workers’ Union and supported Sanders, and according to polls, Sanders has the most support of any candidate among African Americans nationally.

In an enjoyable twist, party rules that were meant to favour the right are now backfiring on them. In the Democratic rule book, you can’t win any delegates if you get below 15 percent of the vote in a contest. In the past, that has usually shut out leftists and prevented them playing a kingmaker role at the final nominating convention. But the contemporary concern with inequality and mistrust of the political establishment is giving a boost to Sanders, so he easily clears 15 percent – and because each of Sanders’ many rivals has something badly wrong with them, they are often sinking below 15 percent and missing out on any delegates at all.

When Chris Matthews worries about being beheaded in public by socialist cyber-bullies, he’s trying to rally the troops to find a way to crush Sanders before it’s too late. There is still a lot of serious resistance. Pete Buttigieg spoke for many when he warned against a return to the “revolutionary politics of the 1960s” – a so-called liberal and the first openly gay presidential candidate complaining about the time when activists challenged Jim Crow, the Vietnam War and sexual repression.

New York Times columnist and Republican never-Trumper David Brooks, the kind of well-educated moron the establishment loves – a man who once fantasised about a new party led by John McCain and Joe Lieberman to rescue US democracy – has warned that a Sanders nomination would represent “the end of liberalism”, because he is a believer in “revolutionary mass mobilization” who works through “rage, bitter and relentless polarization” and “incessant hatred for your supposed foes”.

This makes Sanders sound a lot better than he is. Warmongering neoliberals like Brooks certainly deserve incessant hatred. I wouldn’t mind seeing a revolutionary mass mobilisation in the USA, but there haven’t been any in my lifetime, even at Sanders campaign events. This kind of fearmongering proves that the establishment remain fearful and hostile.

But as things stand, it’s not impossible that Sanders could either win an outright majority of delegates, or so many that a decisive section of the party apparatus chooses to make peace with him rather than rob him of the nomination.

Enduring a Sanders nomination would represent a defeat for mainstream Democrats who desperately want their party to become the number one choice of the US ruling class – that’s the basis of most of their attacks on Trump. But they might be able to find a way to work with it. Ro Khanna, a Democratic congressman and a co-chair of Sanders’ campaign, told the Boston Globe after Sanders’ victory in Nevada that "as we move to him consolidating support for the nomination", Sanders would emphasise more that "these policies will be good for our economic future... He believes in free markets.”

By the time Sanders had declared his vice presidential candidate and started mapping out a campaign strategy, the establishment would have a sense of how much he would be willing to play ball. After all, the once disruptive Trump has now become pretty well integrated into the Republican machine.

If Sanders went into the election as the Democrats’ candidate, he could face even more institutional challenges. He might find himself starved of funds and undermined by a Democratic apparatus that would accept a drubbing in the 2020 election if it helped demoralise another generation of more left wing Democrats and helped swing the party back to the right.

The liberal media have done some preparatory work for this. After four years describing Trump as something close to a second Hitler who must be stopped at all costs, the mainstream media have more recently begun saying Trump and Sanders are hard to tell apart. Sanders being crushed in a general election might be a temporarily effective way to destroy the spirits of anyone who wants a better standard of living for US workers.

But capitalists don’t always get their way in electoral contests. Even if the Democrats and capitalists remain hostile to Sanders, and he doesn’t signal to them that he is willing to compromise, victory can’t be totally ruled out.

As his supporters and opponents often point out, Sanders’ proposed policies would face serious opposition. Even the capitalist-to-his-bones president Franklin Roosevelt, who Sanders often harks back to as a role model, was threatened with a coup in the 1930s.

On the one hand, Sanders would inhabit one of the most powerful political offices in the world: the US imperial presidency, with executive powers expanded dramatically in the post-9/11 age by Bush, Obama and Trump. He might use these powers to make flashy decrees that would establish his bona fides, rather like Trump banning Muslim immigration early in his presidency.

But on the other hand, as people in the US often point out, they live in a system of checks and balances. The US has an ultra-powerful and very political unelected Supreme Court, and two houses of Congress packed with right-wing Democrats and Republicans who together hold a veto over any serious appointment and all legislation.

At each step, these challenges will create huge pressure on Sanders to capitulate to the mainstream if he wants to get ahead. Right now, he’s fighting for the nomination, and he inspires his followers by denouncing oligarchs and the 1 percent even within the Democrats. But if he were to win the nomination, the political calculus would change. Some influential centrist Democrats like Paul Krugman are counselling the party to make peace with Sanders.

But if Sanders won the nomination and the election, defied all historical trends and refused to compromise, and somehow managed to get some of his reforms through – very big “if”s – the USA would still be a capitalist superpower driven to dominate the world by the logic of the global economy. Capitalism would still be capitalism, even if its chief executive were a “socialist” president.

As Sanders points out when he’s trying to appeal to centrist voters, loads of warmongering imperialist societies, run by brutes and experiencing ever increasing inequality, have some kind of universal health insurance. Better health care in the USA would not make the US military or the CIA any more tolerable; nor would even the most extreme versions of Sanders’ Green New Deal be able to avert climate change, when that ecological disaster is so deeply rooted in the structures of world capitalism.

That points to the dangers inherent in identifying Sanders’ politics purely and simply with a revival of socialism. For almost a century, we’ve dealt with the legacy of Stalinist societies identifying as socialist. A Sanders presidency would create a new problem for those who want to overthrow capitalism – socialism would be identified with all the problems caused by the biggest capitalist superpower the world has ever known. The chief commander of the US military and spy agencies would be the world’s most famous socialist.

That’s not to say that none of Sanders’ specific proposals should be supported. But as Sanders points out, his non-radical policies, while supportable, would leave the fundamental structures of US capitalism in place. His campaign in no way reduces the need to wage a separate fight for revolutionary, internationalist socialism, which must be sharply counterposed to Sanders’ misleading vision of a just society – which is really just a mildly reformed capitalism.  If we reduce socialism to mean applying Sanders’ policies – which are already in place in much of the world – in the world’s biggest imperialist power, then we are giving up on the liberation of humanity.

Those who simply see the role of revolutionaries as building a movement to promote Sanders, or defend him from his opponents, are missing the point, and dangerously so. A movement to defend Sanders could easily become a movement to defend all his compromises and betrayals – that’s been a common theme in the history of the socialist movement acting as an extension of electoral campaigns. Movements to defend left-wing bourgeois governments, rather than to fight for the independent interests of the working class, convert the left into passive extensions of the capitalist state.

We need a movement to challenge the very logic of capitalism around the whole world, and that will require fighting to explain that socialism can’t be achieved by any US president. It can be won only by a revolution.