WHAT is Boris Johnson? For many Labour supporters, he’s just a racist clown from the Tory circus.

But I think you need to know your enemy. And that means understanding not just that Johnson is a horrible Tory, but also what kind of horrible Tory.

What kind of circus tricks can we expect him to perform? How do we avoid the squirt from his squeezy flower or the gunge from his bucket?

First, Boris Johnson is not Dominic Raab. The Tory MPs knew that the most-right wing Brexiteer they put to their members would very likely win. So why did they pick Boris, not Dominic?

Raab is one of the five MPs who wrote Britannia Unchained, a Tory book arguing David Cameron should go rightwards from his “Notting Hill” Toryism.

They failed, and switched to trying to use Brexit to launch a neo-Thatcherite slash-and-burn of regulations, spending and workers’ rights.

But Johnson actually rose in the Tory Party as a semi-detached part of Cameron’s Notting Hill set, the supposedly liberal Toryism they hated.

Many Tory MPs and members want to do Raab’s thing. But they are also acutely aware that Jeremy Corbyn is a real electoral challenge because of the lack of affordable housing, low wages, bad work conditions, threadbare schools, hard-up hospitals and fraying public ream.

They know that by itself slash-and-burn is a negative, a vote loser.

The basic plan is that Johnson should drive through Brexit to launch a slash-and-burn of regulations, spending and workers’ rights.

But he should also distract from and alleviate the vote-losing misery of this programme with selective social spending, infrastructure projects and national investment.

They expect Johnson to be able to mobilise the nastiest, illiberal sentiments behind Brexit with his jocular racism, but also to lighten the gloom with some liberal social programmes.

This is why they picked Johnson and why they talk about him  having “optimism,” “vision” and “can-do spirit.”

It is a potentially powerful manoeuvre, but also a difficult one.

It is a manoeuvre Theresa May tried, with her speeches about dealing with “burning injustices” alongside a continuing squeeze on spending. But she never got beyond rhetoric.

Johnson has the opportunism to try this move, but doesn’t necessarily have the skill.

From his time as London mayor, his “social gestures” turned out to be expensive failures, often involving his close mates, like the unbuilt garden bridge.

If you really want to understand how Johnson’s politics are deeply embedded in his past and personal life, Sonia Purnell wrote a comprehensive biography, Just Boris.

It was published in 2011 but fully stands the test of time.

Johnson comes out of the older institutions of the British Establishment — the ones that have got stale and rotten.  

Johnson went to Eton, where he was a member of an elite within the elite. He was a member of an Eton sixth form club called Pop, made up of the most “popular” boys.  

Pop members wear a uniform of special checked trousers under their tailcoats and have privileges including their own clubroom and being allowed to stay later at “Tap” — Eton schools own sixth-formers’ bar.

He went from this absurd Establishment institution to other absurd establishment institutions — Oxford, the Bullingdon Club, The Times, the Spectator, the Telegraph, on a wave of privilege and entitlement.

This has made him a sneering snob. Johnson described Portsmouth as “full of drugs, obesity, underachievement and labour MPs.”

As Spectator editor, Johnson published an article about Liverpool saying the city suffered from a “tribal sense of community,” and while lying about the number who died in the Hillsborough disaster, said the deaths left Liverpudlians in “the mawkish sentimentality of a society that has been hooked on grief and likes to wallow in a vicarious sense of victimhood.”

Sneering at regular folk, Johnson has always stood up against “banker bashers,” enthusiastically supporting low taxes and less regulation for the City, even after the 2008 crisis.

Johnson also learned opportunism early. He ran for the presidency of the Oxford Union in 1984, but his Tory campaign focused mainly on ex-public schoolboys.

He was beaten by a “left-wing” campaign led by the SDP (this was Oxford), which canvassed heavily among the half of students who from state schools (called “stains” by public schoolboys like Johnson).

Shocked, Johnson ran again for Oxford Union president in 1985, and won by campaigning as if he was also an SDP supporter, giving a speech arguing that “we have had enough of two-party politics.”

Johnson later wrote that he won that 1985 Oxford Union election with the help of a “disciplined and deluded collection of stooges” because “the terrible art of the candidate is to coddle the self-deception of the stooges.”

This cynicism and opportunism have stuck with Johnson, as he has posed as both left and right.  

In the 2005 Conservative leadership contest, Johnson said: “I am supporting David Cameron purely out of cynical self-interest.”

The Tories trust Johnson because his pure Eton, banker-loving Toryism is deeply ingrained.

They did not trust his opportunism, but they are in such a corner they now see his lack of principle as an advantage.

Johnson might make liberal gestures, but this opportunism cuts both ways. He is as likely to use racist or sexist attacks if he thinks it will help.

He played “Tory leadership” like a game and is willing to use any “cheat codes” or adopt any character to complete the mission. He will do the same as prime minister. Getting caught up in his drama is part of the game.

It might be better to remember why the Tories are gambling on Johnson: they fear their message of low spending for the poor and low taxes for the rich has little appeal, so they want a clown to distract from the miserable state of the circus.

We need to avoid getting to drawn into conversation about the colour of his wig or size of his big red shoes, and keep focusing on how Labour can change conditions for the audience in the big tent.