The reason Jeremy Corbyn is not preparing to lead the first majority Labour government since 2010 is Jeremy Corbyn. The Labour leader is proving the falseness of the cliché that ‘oppositions don’t win elections, governments lose them’. Unless enough people are convinced of an opposition’s competence and decency it will not take power, even when all it has to do is beat the mendacious rabble that make up today’s Conservative party.

Jeremy Corbyn’s opposition did not win a majority and could never win a majority because millions could not vote for the incompetent and indecent Jeremy Corbyn. It’s that simple.

I am not just repeating anecdotal evidence from Labour MPs and canvassers. A vast poll of 12,000 voters, released tonight, showed Jeremy Corbyn was by far the single biggest reason voters gave for deserting Labour. Of those who voted Labour in 2017 but were less than 50 per cent less likely to vote Labour now, Deltapoll found the overwhelming reason people gave was they ‘don’t like Jeremy Corbyn’ with 46 per cent agreeing with that blunt statement.

As tonight’s epic defeat shows, Labour could not win because of Jeremy Corbyn and the rancid political clique he led. Do not underestimate the scale of the rout for a moment. Johnson’s triumph is absolute. The Conservatives could be in power for most of the 2020s because a bunch of student politicians and narcissist performance artists destroyed a once viable party.

This election is the foulest of my lifetime because of the willingness of politicians to play with the existential fear of minorities, and for their supporters not to care. How many Conservatives protested when Boris Johnson denounced EU nationals for treating the UK like 'their own' country for too long? That would be EU nationals who have in many cases lived here for decades, who have worked here, paid their taxes here, loved, married and raised children here. The EU nationals who, until the Brexit referendum, never had the smallest suspicion that their security and sense of who they were and where they belonged could be thrown in the air. How many Conservatives have noticed or cared that Johnson promised during last year’s Conservative leadership election to hold an inquiry into Tory Islamophobia, only to break his word once he was safely in Downing Street?

Then there are the Jews. I have friends and colleagues I once considered good people, and politicians and celebrities I once admired, who I can never look at the same way again after they endorsed Labour. Not reluctantly, not as a grim but necessary compromise, but joyously with the absurd conviction that the collection of creepy and half-witted conspiracy theorists they sold their souls to could end poverty and restore the shattered public realm. To support Labour with a smile on your face was to say anti-Jewish racism doesn’t matter. It doesn’t shame you or them. You don’t care about it anymore than the supporters of Donald Trump cared about the pornographic treatment of women, the anti-black conspiracy theories about Obama being a fake American and the Muslim travel ban.

Inevitably, given European history, this generation of British Jews are thinking that this is what it is like when they come for you. Respectable people, your friends, your neighbours, look away. They don’t listen or want to listen. When they come for you, you find you are dispensable.

‘The ease with which you turned on us, may it be a stain on you for the rest of your miserable lives,’ cried the Labour activist, Dan Fox to Labour members. ‘As our grandparents would say, ken der veytik in aundzer hertser geyn tsu deyn kef – may the pain in our hearts go to your heads. We were your comrades. And you betrayed us to people some of whom have still never lifted a finger for this Party of ours. You sold us out. You abandoned us. Damn you to hell. We were comrades.’

I am pleased to report that the despairing idea that Jews are on their own is not true. The Jewish Leadership Council commissioned the poll and, naturally, asked about Labour racism.

Among 2017 Labour voters who were uncertain about voting Labour in 2019, anti-Semitism was almost as big a reason as Brexit for people turning away from the party. 16 per cent gave anti-Semitism as a reason while 19 per cent named Brexit. Over a quarter of the entire voting population – 28 per cent – said they would have been more likely to vote Labour if Corbyn had handled accusations of anti-Semitism better.

Nearly half – 40 per cent – of Labour 2017 voters said they thought a different Labour leader would have handled the scandal better. Indeed, researchers told me that even focus groups of hardcore leftists complained about the inability of the leadership to ‘close the issue down’. They lacked the character and intelligence to admit that conspiracy theory is essential to the project they are wasting their lives on. But if they could not see the moral objections they could at least bemoan the political ineptitude.

Of those who voted Labour in the 2017 election, 29 per cent felt that Labour has a problem with anti-Semitism. 11 per cent said they felt both Corbyn himself and the Labour Party were anti-Semitic, while another 14 per cent said that while Labour wasn’t anti-Semitic Corbyn himself was personally anti-Semitic. A large majority of the public blame Corbyn personally for the scandal, with 59 per cent saying he had been ‘incompetent’. Among 2017 Labour voters, that figure was 37 per cent. Over a quarter – 26 per cent – of Labour 2017 voters said that accusations of anti-Semitism within the Labour Party made them ‘embarrassed at the state of British politics’ while 17 per cent of 2017 Labour voters said that it had made them 'worried about increasing racism in society'.

In other words, Labour politicians and activists should not think for a moment that there has not been a price to pay for their descent into the mire. Not a high enough price, in my view, but a measurable cost, which to their shame they were either too stupid or too racist to realise would be added to their bill. The rest of us can find a little cheer at this miserable time. It turns out that, despite everything, the British aren’t such a bad lot after all.

Sample Size for the poll was 12,147. Fieldwork by Deltapoll for the Jewish Leadership Council was carried out from 29 Nov to 2 Dec 2019. Tables will be published at http://www.deltapoll.co.uk/.