I cannot tell you how influential and damaging the consoling belief that Britain is a “progressive” country has been. It stopped the Left being frightened of the Right. It stopped it taking the fight against it seriously. In his bedtime story for lefties, The Conservative Dilemma, Jon Trickett, an ally of Miliband, argued that the Tories could not cope with the 21st century. They couldn’t appeal to their base without appalling the “progressive majority”, or vice versa. Miliband’s Labour, he wrote in 2012, was now free to renounce the compromises of the hated Blair era. It could let rip, march leftwards, and “put an end to triangulation on to Tory territory”. Every assumption he and thousands like him made has now turned to dust.

Maybe you find these Left/Right divisions arbitrary. When you ask them to describe themselves, the overwhelming majority of sensible people do not use political labels. But nearly everyone knows which country they belong to, and national as much as political divisions destroyed the British Left last month.

The SNP swept Scotland by appealing to Scottish patriotism. Labour was a quisling party of foreigner-loving traitors, it said; “red Tories” who would sell out Scots to their English enemies. Labour tried to argue that the SNP, a movement supported by Rupert Murdoch, was hardly left-wing. It tried to raise the disgraceful state of Scotland’s schools and hospitals under SNP rule. No good did it do them. Nationalism thrashed social democracy, as it has done so often in the past. South of the border, Conservatives and the Kippers hit Labour with English nationalism. Far from being “red Tories”, Labour would ally with the “far-left” SNP and do down the people of England, they cried. Once again Labour were the quislings, the enemy within, only this time the charge was coming from English rather than Scottish nationalists.

I said earlier that Cameron was an inadequate prime minister unfit to meet the challenges of our time. Nowhere in my view is his mediocrity more evident than in his willingness to risk the union by setting up an arms race between Scottish and English nationalism. But why should he care? In the short term, which is the only term that matters to him, who can deny that his tactics worked, and that Labour could not cope with them?

After the election I wrote in the Observer that Labour was in crisis because the English Left, almost alone in the world, has got itself into a position where it has to pretend that it cannot abide its own country:

 
The universities, left press, and the arts characterise the English middle class as Mail-reading misers, who are sexist, racist and homophobic to boot. Meanwhile, they characterise the white working class as lardy Sun-reading slobs, who are, since you asked, also sexist, racist and homophobic. The national history is reduced to one long imperial crime, and the notion that the English are not such a bad bunch with many strong radical traditions worth preserving is rejected as risibly complacent.

It was worse than I said at the time. I should have remembered that after Scotland received greater autonomy Labour pulled every trick it could think of to stop England receiving compensatory powers. Its self-interest was transparent. Labour had to apply a double standard to England and allow Scottish MPs to vote on English laws because such a large proportion of its politicians were Scottish. At the election, it suffered for being seen as an anti-English party, while watching its mighty Scottish contingent reduced to one MP — a nice chap from Edinburgh called Ian Murray.