To state the obvious up front, Hillary Clinton is going to win the Democratic nomination. There is almost no permutation of the various demographic, political and procedural factors in the upcoming caucuses that permits any other outcome; barring radical shifts in the political landscape or the breaking of huge, unexpected scandals, there’s no way you can run through the maths and arrive at delegate totals for the Democratic National Convention in late July that hand the party’s candidacy to anyone other than Clinton. Anyone predicting or even simply hoping for a different outcome is, of necessity, predicating their hopes upon a black swan – an entirely unpredicted shift in support or the breaking of an as-yet-unknown scandal – and while such things can and do occur, especially in the unpredictable mire of the systematic weirdness of the US’ primary system, they’re not a wise thing to base your predictions upon. So, to hedge slightly; absent something utterly crazy happening, Hillary Clinton is going to win the Democratic nomination.

That’s not to detract from the scale of Bernie Sanders’ success in Iowa. As I type, Sanders is 0.2% behind Clinton in the caucuses, 49.8% to 49.6%, with only a handful of counties still to report. It’s a rounding error; as close to 50:50 as you’re likely to get in the peculiar and inaccurate delegate system used in Iowa’s Democratic Party caucuses. Though even such a tiny margin will allow the Clinton camp to declare a victory, Clinton and Sanders will split the state’s 42 delegates half and half.

Why, then, call this a success for Sanders? Because six months ago, the polls (I’m using FiveThirtyEight’s excellent aggregated polls) gave him around 22% of the vote in Iowa, to Clinton’s 54%. Three months ago, it was 32% to Sanders, 54% to Clinton. A month ago, on January 1st, it was 36% to Sanders, 52% to Clinton. Sanders topped 40% for the first time three weeks ago. Today, in the actual caucuses, he’s on 49.6%. In the past six months, Clinton has dropped 6% in Iowa, and Sanders has surged 29% – suggesting that undecided voters are breaking strongly for the Sanders camp, and a small number of Clinton supporters are changing sides.

It’s not enough to win the nomination. David Wasserman at The Cook Political Report rightly observes that in order to actually win in July, Sanders needed to do much, much better in Iowa, a state whose demographics are much more favourable to him than many of the upcoming states. Sanders resonates with white liberals, while Clinton enjoys a strong base of support among ethnic minorities; it’s easy to forget that the Democratic Party isn’t just the party of white liberals, but also the party of many ethnic minorities who do not share the same degree or form of liberalism as white Democrats. This isn’t to say that those support bases might not move around – Sanders’ momentum could yet give him a boost within groups that have thus far stayed strongly loyal to Clinton – but based on track records thus far, most upcoming races (with the exception of the New Hampshire primary next week) ought to be far easier victories for the Clinton camp.

Nonetheless, Bernie Sanders has accomplished something hardly anyone expected him to; he has turned the Democratic primary into a contest rather than a coronation. Only a few months ago, there was a strong movement to try to “draft” outgoing Vice President Joe Biden into the nomination race, largely because Democrats feared that turning the whole thing into a state-by-state victory lap for Clinton would look extremely bad; voters, the conventional wisdom goes, want to see candidates fight for the nomination, and hate the sense of being handed a candidate anointed by the “party elites”. At that point, Sanders was a rank outsider; a self-declared “socialist”, the reasoning went, could never present more than a distraction, acting as a magnet for a minority of malcontents and fringe voters rather than a genuine contender.

Well, Sanders just came neck-and-neck with Clinton in Iowa, and short of an act of god, he’s going to win New Hampshire next week. The Clinton camp won’t be panicking – she’s still got this in the bag – but the Democrats have a race on their hands, even if it’s a much more politically interesting and ideologically divided race than the somewhat tame pot-shots between a handful of centre-left candidates that the party establishment might have wanted.

Two things are important for the Sanders campaign from here on out. The first is to avoid isolating Sanders too far from the mainstream of the Democrats, for the simple reason that his ability to influence American politics rests not on winning the nomination (which he almost certainly won’t) but on pulling the Democratic Party’s discourse to the left by energising and revealing the breadth of support for more left-wing policies than were previously considered palatable to the party base and, more broadly, to the American electorate. Sanders doesn’t have to win for his policies to win; if his success and momentum proves major support for policies like free college education, those policies can be integrated into the Democratic Party’s mainstream agenda, assuming that Sanders’ campaign hasn’t isolated itself too far from the party mainstream. Thus far, Sanders’ civil and gracious campaign has done a good job of this; assuming things don’t turn very negative in future, there’s a reasonable chance that Sanders’ most popular policies (and perhaps even Sanders himself) could be a part of a future Clinton administration.

The second thing the Sanders campaign needs to do is to keep up its momentum and energy, not because it’s going to win off the back of those things, but because it needs to be in position to catch the ball if – if – Clinton drops it. A huge scandal (something we don’t know about – email improriety and conspiracy theories about Benghazi don’t count, as any negativity resulting from them is a) largely confined to Republican voters anyway, and b) already baked into Clinton’s polling numbers by now) could upset the apple cart; the Sanders campaign needs to be firing on all cylinders for a couple more months, just in case. It’s not wise to base your political predictions on black swans; it’s equally unwise to leave yourself in a position in which you’re unable to capitalise upon a black swan if one should hove into view.

While the American commentariat is losing bowel control in shock at a socialist – a socialist! – being even an outside contender in a high-profile primary race, Sanders is arguably most interesting when you consider him in a global context. In the context of other developed nations, the emergence of a more radically left-wing candidate with strong support, especially from young voters, isn’t shocking; it’s perfectly in keeping with the patter of the past five years. Across Europe, the New Left has surged, starting in countries most traumatised by the financial crash of 2008 but growing in strength in nations simply suffering from the widespread malaise of the world’s developed economies – where decades of neoliberal policies have almost completely decoupled GDP growth from income or quality of life improvements for most of the population, and especially for younger people who face a markedly more insecure and uncertain future than their parents’ generation did. The success of Bernie Sanders in the US is, in this context, a mirror for the success of Jeremy Corbyn in the UK or even the recent resurgence of Kazuo Shii’s Communist Party in Japan; signs, perhaps, of the Millenial generation (born in the 80s and 90s) rejecting the neoliberal consensus of their immediate predecessors (Gen X, those born in the 60s and 70s) and turning to “outsider” figures, rejected by Gen X and the Boomer generation, as an immediate alternative. It’s notable that Sanders, Corbyn and the Japan Communist Party are all rather venerable; their messages aren’t new, they’ve simply finally found a generation with whom they resonate.

There are, however, essential differences between Sanders and his overseas counterparts in the New Left – not least that American politics is a rather different environment. Most notably, the New Left in most countries has had an untapped well of young people engaging with politics for the first time to draw upon; in many countries, voting turnout among under-35s (the Millenials) has been tiny, and energising this group to turn up and vote that has produced such remarkable results as Jeremy Corbyn’s election as UK Labour Leader. In America, though, this well has already been tapped, to some degree; Democrats already had a “Corbyn moment”, way back in 2008 with Barack Obama. A significant cohort of Millenials boosted Obama in 2008; some of those may wish Obama had been more radical, and side with Sanders, but the reality is that Obama’s approval rating among Democrats is pretty great, and the natural flow for Obama supporters who approve of his record is to back Clinton, the key member of his administration, not Sanders, the radical outsider. Sanders still does very well among the young, but they’re not the untapped wellspring of radical support that they have transpired to be in the UK and across Europe.

One final thought. Older voters may roll their eyes at the radicalism of the Millenials, but I think a great many older voters genuinely fail to comprehend the economic mess that faces the Millenial generation, who are bearing the brunt of some disastrous and short-sighted policy-making dating back as far as the 1980s. No post-war generation in the developed world has ever been expected to pay so much for education, or been greeted with more uncertain employment prospects after graduation; no post-war generation has faced so many formerly “middle class” occupations being reduced to low-paid, short-term, unstable work; no post-war generation has faced such a dizzying ratio of housing costs to average wages, or such a grim ossification of social mobility. The Millenial generation is, for the most part, saddled with huge debts and told to repay them with earnings from the least worker-friendly labour market in post-war history. That they would turn to alternative politics for solutions is entirely unsurprising and reasonable; it’s the notion that the existing neo-liberal business-as-usual consensus can continue under these circumstances that is ridiculous.

Given that, the eye-rolling should perhaps be replaced by sighs of relief, because populations under severe economic pressure do not necessarily flirt with the radical left; there is a far uglier alternative on the radical right. In the 1930s, economic catastrophe for ordinary people drove them towards radical-left and radical-right solutions; the radical-right won the day in many countries, and, well, the 1940s happened. Today’s radical-left solutions, shorn of the dead-end revolutionary ideology that made the far-left just as unpalatable as its far-right counterpart in the 1930s, are a much more appealing thing for the set-upon Millenials to flirt with than the far-right alternatives – which, based on the rhetoric of the Right across Europe and the USA, have evolved far less in the past 80 years and represent a far greater threat to democracy, stability and security.