No one listening to Brendan Cox’s interview on BBC Radio 4's Today programme this morning could fail to be touched by what he was saying about the way Jo Cox’s name and memory has been used and abused in the House of Commons. The contemptuous manner in which Boris Johnson dismissed others MPs’ distress and fears of death threats as “humbug” was unusually offensive, even by his standards.

It was ludicrous for him to make out that the best way to honour Jo Cox’s memory would be to “get Brexit done", breathtaking in its audacity, and the emotional responses to that remark were visceral. After all, Jo Cox was assassinated while campaigning for Remain during the 2016 referendum – and event which, for a time, stopped the clock.

Her widower has appealed for some calm, and for everyone to recall Jo's abiding testament: “We are far more united, and have far more in common with each other, than things that divide us”. He regrets that the Brexit debate has descended into a “bear pit of polarisation”.

Brendan is right about that, but the political polarisation he refers to – and the exploitation of it – is quite deliberate, and has not yet peaked. Johnson will see to that.

The polarisation of the debate is intensified by the prime minister all the better to mobilise his own “base” of support: increasingly embittered and frustrated Leavers. He wants them to turn out and vote for him on some dank evening in November. He wants to get them angry.

Thus, he actively wants to be seen battling with parliament – and especially opposition MPs – in the name of “the people”; that is, Leavers. The optics, as they say, suits him fine.

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Johnson is battling, or rather wishing to appear to be battling, valiantly against a vast “Remain Establishment” conspiracy, a “zombie parliament”, terrorist-sympathising Labour leaders, the mainstream media including what he’s termed the “Brexit Bashing Corporation”, and, now, the judiciary. If he thought he could get any traction with it, no doubt he’d chuck the Queen under the bus as well.

“Dog whistle” politics are nothing new for the man who used to write about “picanninies" with "watermelon smiles” and Muslim women wearing “letter box” veils. He knows what he is doing, and what he has been doing for some time now is following the ruthless advice of Dominic Cummings and Lynton Crosby. Their trade is division and their currency hate. When a turbaned Labour MP, Tanmanjeet Singh Dhesi, savaged the PM in the Commons for his racism, a lot of Johnson’s supporters would take Johnson’s side. Liberals have to realise that.

So when Brendan Cox, and well-meaning figures such as Amber Rudd and Stephen Kinnock, start talking about reaching out, building consensus and reaching compromise they have Johnson’s electoral tactics plain wrong.

On Brexit – as John Curtice as pointed out, and the current atmosphere also speaks for itself – there is no middle ground to appeal to in the traditional Left-Centre-Right spectrum of conventional politics. The bell curve has been replaced by twin peaks; the votes are found in the extremes (and that is one reason why Labour's Brexit compromises fail to get much support).

This is a polarised culture war. The only way to win a war like that is to make the other side as angry as your own side in a sort of perverse process of political symbiosis. You need to start fires, and watch them spread.

Seeing Johnson wind up the Remainers and insult these venerable justices and flail the “surrender act”, the “collaborators”, “traitors” and Brussels is just what he needs to recruit these voters – many of them Labour, ex-Labour, ex-Ukip or Brexit party sympathisers – into the Conservative camp. The politics of division thrives on discord and division. It abhors harmony and enjoys the insult.

Brendan Cox wishes us to believe that Johnson is not “evil”, which is admittedly not exactly lavish praise, but then again Johnson is not exactly St Francis of Assisi either. The short word for it is “populism”.

Welcome, in other words, to the new politics. Remind you of anyone?

Obviously Johnson, more or less self-consciously, seeks to be the British Trump, or, as Trump once put it himself, “Britain Trump”. Both men like to have the last word, enjoy upsetting their moments, insult anyone and any institution that gets in the way, double down when they are criticised or attacked, and never, ever apologise or show contrition. They never display “weakness” – or, I should clarify, what they regard as weakness.

The lies flow from the pair of them as they rarely have before in modern political life. When they are checked by opposition politicians (including those in their own parties), or by the “mainstream media” or even by independent regulatory bodies, the response is mainly to attack the motivations and interests of those involved.

Johnson would like to be as good at this as Nigel Farage already is, and the prime minister has all the advantages of incumbency to bring to bear on that task. He has also gathered round him a gang of like-minded men and women, some of whom (Nicky Morgan, for example) should really know better.

So bring on the court cases in DC and Westminster, and the parallel threats of impeachment.

Bring on the accusations of personal impropriety, the mixing of private interests and public money, and the accusations of collusion.

Bring on the fussy talk about independent judges and the rights of a free press, and an effective legislative opposition.

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They can all be vanquished in the name of the majority, the mandate of the “the people”. In both cases it is narrow or non-existent; Trump, after all, lost the US popular vote and no longer controls Congress. Johnson was elected by approximately 90,000 Tory activists, and has never led his party into a general election. Since he has been prime minister he has lost his majority in the House of Commons (so no wonder he thinks it a “zombie”, though it is anything but in practice).

No matter the 52 per cent to the electorate who voted for Leave have been co-opted, willingly or not, into an increasingly radicalised army of populist revolt, who are supposed to want (every single one of them) a no-deal Brexit if necessary, even though they have never been explicitly asked that. They are supposed to believe that they are in a war to save Britain. Hence all the militaristic language. If someone was brave enough to remind Johnson that Jo Cox died at the hands of a man yelling “Britain first” and “keep Britain independent” he would throw the words back in their face as “humbug” or some such.

There is nothing, in fact, that Johnson would not rather than to be arrested for breaking the Benn Act when he refuses to request the article 50 extension from the European Union that he is required to by law to seek. Far from being ashamed to be the first serving premier to have his collar felt by the boys in blue outside Downing Street, he would be delighted. He would get the cameras in to witness every moment of the court order being served. He would then declare himself Britain’s first “Brexit martyr” (with no hint of irony about Jo Cox). He would clown around, and his base would love it. The more of the 52 per cent of 2016 they can convert into Tory voters, the better.