It is remarkable what a difference a single election can make. Even if you lose. Jeremy Corbyn delivered his third – and best – speech as Labour leader to a party giddy with optimism. By reducing the Tories to minority government and increasing Labour’s vote by the biggest amount since 1945, Mr Corbyn has transformed gloom to cheer. That the Labour leader has done so from the left is a vindication of his brand of “modern, progressive socialist” politics. Mr Corbyn’s attachment to socialism is important: since the 1990s Labour leaders have avoided mentioning the word, which they viewed as being synonymous with the then unpopular notions of state control and higher taxes. They preferred instead to declare their loyalty to democratic socialist “values”. Values are less controversial than policies. Values can be shared, whereas policies divide. However, Mr Corbyn’s speech was peppered with plans to intervene in markets where vested interests, represented by the Conservative party, have conspired against the multitude. The Labour leader wants to distinguish his party from the thinking of the last four decades, arguing for a “new model of economic management to replace the failed dogmas of neoliberalism”. His contention is that the party is now electable because of socialism, not despite it.

This is stirring stuff. There’s little doubt that Mr Corbyn spoke to the passions of the party, but did he speak to the preoccupations of the wider electorate? His diagnosis is founded on unquestionable truths: that an era of deregulation, privatisation and low taxes for the wealthy came tumbling down with the global financial crisis. Bankers played a leading role in the crisis, but it’s the rest of society that has paid for the crash. This has had profound consequences: most notably class divisions have been politically revived. “Them and us” economics is rooted in the fact the top 1% of society has recovered all the ground it lost while the average worker faces the longest period of falling real-terms pay since the Napoleonic wars. It’s difficult to sell capitalism to those with no capital.

The symptoms of the malaise are clear and Mr Corbyn’s bold claim is to have the cure. The medicine prescribed by the Labour leader is uncontroversial elsewhere. Rent controls for housing are coming into force in Scotland to deflate ballooning rents. Public ownership of utilities is a mainstream view in western Europe. Labour’s reversal of corporation tax cuts would merely return the rate to its 2011 level and still leave companies shouldering a lighter burden than they do in bigger European economies. The party should be congratulated for debunking the idea that decreasing corporate taxes is the only way to increase investment.

What is fascinating about Mr Corbyn’s speech is its hidden depths, most notably on possible “alternative models” to capitalism. The Labour party sees in the future not just the rise of robots, which might entrench economic feudalism, but also the worry that too many people will remain trapped in drudgery-filled, low-productivity jobs. Although Mr Corbyn did not spell this out, he referenced a little-publicised party report that fleshes out Labour’s view of the new economy. This states that accelerating automation is a key political project. Labour’s goal, the report argued, should be to accelerate into this more automated future “while building new institutions where technological change is shaped by the common good”. Mr Corbyn’s socialism is evidently more intellectually bracing than previously countenanced.

Oratory is not shallow or frivolous – it is at the centre of our political process. Mr Corbyn has inspired the faithful by telling party members what they want to hear. His plans are premised on the idea that “there is a new common sense emerging about how the country should be run”. This “common sense”, a phrase significant in any attempt at political and social transformation, challenges the idea that the truths of society can be found only in markets. In proving electorally successful, Mr Corbyn can lay claim to have expanded the epistemic range of public debate. Ideas once thought unsayable have become acceptable. This year was when the crisis in economics caught up with the crisis in politics. But the future contains the biggest issue to face Britain since the end of the second world war. Mr Corbyn’s gnomic utterances on Britain’s long-term relationship with Europe were telling. Labour’s muddled thinking is obscured by the shambolic approach of a ruling Tory party fractured over Brexit. The Labour leader has proved he can lead a congregation. But he will need a broader message to convert the masses.