If you wanted a clue to how much the Labour Party has changed over the past few years, you wouldn't have had to sit through much more than the first few lines of John McDonnell's conference speech. He started it with the words 'I'd like to thank Ken Loach for that wonderful film'. Loach hasn't been the most loyal supporter of the Labour Party over the years, but is now firmly back in the fold thanks to Jeremy Corbyn. Party members, normally tribally opposed to those who set up rival parties, gave the veteran filmmaker a standing ovation.
The Labour Party has been changing for a while, but this conference is showing that it is now comfortably settled into its new Corbynite skin. Loach's film had been preceded by a delighted reception for Dennis Skinner, and was followed by McDonnell's speech in which he pointed out how many people had been wrong about Labour's political prognosis in the tones of a man whose party had just won an election, rather than lost it pretty well.
Because Labour did lose the 2017 election well, it is in its least apologetic mood for years. It can promise, as McDonnell did, to spend a whole heap of money on renationalising a whole range of industries, while also claiming it will cut the deficit and not see any paradox there. 'Rail, water, energy, Royal Mail - we're taking them back!' promised the Shadow Chancellor to huge cheers.
Interestingly, his big announcement designed to delight members wasn't one designed to cause a big political row. McDonnell promised to bring existing Private Finance Initiative contracts back in house, telling the conference that 'I can tell you today, it's what you've been calling for'. Members were delighted that a monster of politics was being slain - but outside the conference hall you will struggle to find many passionate defenders of the PFI programme. It's not something many Conservatives will really want to die in a ditch over, and so it is designed to show Labour members that they're the most important people in the party leadership's mind, as well as suggesting that the party is interested in ending money-wasting policy failures.
The hall today had the happiest atmosphere of any since the party left government. The members and party workers who thought that such a spending bonanza might cost them the next general election were keeping their views firmly to themselves. They now know that their party's new identity is sealed, and there is little reward for anyone who tries to challenge that this week.