Cameron’s speech shows how Corbyn is making this a more left-wing country

Of all the various predictions of a left-wing disaster following the election of Jeremy Corbyn, few commentators noted the effect he might have on the Tory party. His election has dragged the Conservatives to the centre, and dragged the centre to the left. It produced today's extraordinary speech from the prime minister, in which he finally lived up to the moniker 'heir to Blair'.For the first time he is genuinely moving his party to the centre – as his hero did – rather than just paying lip-service to it.

This was the best speech David Cameron has delivered as Tory leader. It was one of those rare speeches which managed to accomplish several things at once. It painted a meaningful portrait of the kind of country Cameron was trying to create, assisted his internal allies while diminishing his enemies, boxed the Labour party into a corner and created an election-winning message for 2020. Cameron made the most of every opportunity offered to him by the general election win and Corbyn's selection as Labour leader. He has never looked more comfortable or happy.

In fact, he was so confident he strayed close to becoming smug. His prolonged recollection of election night was painful in the extent of its back-patting. His delivery is still workmanlike and competent, but not special. He is not a great orator and never will be.

He also has a strange inability to properly use rhyme or comparison. Several soundbite lines scan terribly, among them: "Labour: you're not for working people, but hurting people." There was also a painful sex joke about the Richard Murphy book 'The Joys of Tax'. "I took it home to show Samantha. It’s got 64 positions. And none of them work."

Mrs Cameron grimaced at that, as well she should. Her role at these events makes it seem like she has been cut out from a 1950s housewife magazine and pasted onto the modern world. She must walk with her husband to the conference centre, look on longingly as he speaks, laugh as he makes smutty jokes about her, then go on stage and smile as he points at imaginary objects in the middle-distance. She is silent, a human prop for him to demonstrate his normalcy. Corbyn and Tim Farron have both dropped this appalling tradition. Cameron must now do so as well. It is increasingly grotesque and embarrassing.

But that's where the inadequacies ended. In every other aspect, this was a barn-storming and triumphant speech. Cameron may not be able to emulate Blair's presentational abilities, but he is quite able to reach deep into enemy territory and plant his flag there.

He condemned the social failure which allowed children in care to so often lead broken, poverty-stricken lives, he promised prison reform so that incarceration was based on rehabilitation instead of punishment, he pledged more social mobility, lambasted the de-facto segregation which besets some British communities and outlined a Danny Boyle-style, modern, inclusive vision of British patriotism: "The proudest multiracial democracy on earth".

The policy was either contradictory or absent. Taking over failing social services will not be the panacea he imagines. The money needed to build new prisons won't be available from selling of the ones we have and anyway – the rehabilitation he imagines requires fewer people going to prison, a reality he was not prepared to admit, although a comment on electronic tagging suggested we could see movement here in future. The social mobility he envisages becomes less likely due to cuts to public spending – not least of all the cuts to tax credits he is still planning on implementing. The segregation he wants to destroy is cemented by faith schools, which he is unwilling to ban, settling instead for greater oversight. And his anti-extremism programme in schools is so vague as to be a major threat to freedom of speech.
Scratch beneath the surface and the policies are not there. But this is a conference speech – as much about rhetoric and signalling as it is about specifics. And some of the language was extraordinary. A passage about racial and gender equality was genuinely moving. "I’m a dad of two daughters – opportunity won’t mean anything to them if they grow up in a country where they get paid less because of their gender rather than how good they are at their work," Cameron said. And for a moment, you actually believed that he meant it.

Cameron did not move left in a manner which seemed forced or nakedly strategic. He framed the shift in patriotic sentiment. He was not just occupying ground vacated by Labour – he was defining it in the terms most damaging to Corbyn and most comfortable to his own party. The Labour leader's failure to sing the national anthem was the DNA of this speech. It was in every line. Cameron went in hard on security as a lullaby to the right, then framed his vision of "freedom, democracy, equality" in patriotic terms. He had his cake and he ate it and he convinced the conference to not complain too much about the menu either.

Even as he reduced Labour's chances of ever winning in 2020, he was also laying the ground work for his preferred successor in 2018. The praise for children of immigrants at the Cabinet table – Priti Patel and Sajid Javid – as well as his celebration of a "multiracial" society was a riposte to Theresa May's hard-right anti-immigrant speech. The centrist message of George Osborne was clearly far more in line with the direction he was steering the party.

It was a full-house speech, accomplishing several tasks with each line: debilitating his opponents, positioning the party for electoral success, expressing a clear philosophical position and doing all of it with genuine rhetorical flair. It was everything Corbyn's speech wasn't: structured, tactically intelligent, convincing, thematically rich and capable of convincing those outside your core support of your argument.

As such, it will be treated as further proof of the insanity of Labour members for choosing Corbyn. But actually the speech demonstrated why Corbyn is a good thing for the British left, even if he is not a good thing for Labour. His move to the hard-left drags the Tories leftward too. This was a far more left-wing speech than Cameron would have delivered if Liz Kendall, Andy Burnham or Yvette Cooper were scrapping with him in the centre ground.

If, as a left winger, you are aiming for the best possible outcome of a Labour government, the election of Corbyn is not helpful. If you are instead trying to minimise the worst possible outcome, then his election has been a tremendous success. Corbyn may not get elected. But today's speech shows that his opposition creates a more left-wing political climate.

If Margaret Thatcher's greatest achievement was New Labour, Corbyn's might be the new-look Tory party.