Constantly inconstant, Boris Johnson is faithful in at least one area: generating outrage. That he does as naturally as a dog cocks its leg at a lamppost.

This week, he has used the bodies of those murdered at London Bridge as props for his election campaign. Last week the 55-year-old dodged a Channel 4 debate on climate change, sending instead his dad and his wingman, Michael Gove. And then there are his many columns, spitting at gay men (“tank-topped bumboys”), single mums (“uppity and irresponsible”) and black people (“smiling piccaninnies”).

I would go on, but equally so might you – and we both know what typically comes next. The performative pearl-clutching, the saucer-eyed wailing: “How could he?” The sound and rote fury on social media and rolling news, followed by a satisfied, full-bellied silence as grateful journalists wait for their next steaming dollop of Boris buffoonery.

Johnson may be a rogue, but what should worry us is that he is a risk to our economy, society, and democracy

It passes time and it pads out columns, but it is no way to scrutinise the man who may well be our next prime minister, in charge of taking Britain out of Europe into a new era of foreign and trade relations – and rewriting our political, economic and social settlement. With the president of America strutting around London this week, the comparison is inevitable. Over this election, Johnson is playing the media and the public just as Trump did before claiming the White House in 2016.

Both men are adept at exploiting the media appetite for offence over ideas, for name-calling in place of nuance. Trump calls Elizabeth Warren “Pocahontas”; Johnson likens Jeremy Corbyn to Stalin. Ridiculous, of course, but enough kindling for at least two days’ headlines. The US president calls his counterpart in No 10 Britain Trump, and both men have made the same calculation. The cash-strapped media needs eyeballs, and these two enjoy having all eyes on them – so they grab coverage and set the terms of the debate.

If Johnson makes a show of himself, at least he’s the star. When he has a car crash, websites thank him for the traffic. With the biggest UK newspaper groups already behind him, the Conservative leader thus ensures he gets both total control of the message from his friends and the total attention of everyone else.

Who cares if they call him Pinocchio? As a journalist he made his name with tales taller than Michael Jordan – yarns about how Brussels was designating snails as fish, or imposing a maximum size on condoms. Decades before Mark Zuckerberg came along, Johnson had already gleaned the attention economy’s golden rule: professional reputation matters less than providing distraction. Did anyone say zip wire?

This is nothing to do with appearing prime ministerial: it’s about grabbing power. Like Trump, Johnson has no interest in wooing all bases. I have written here before about how the Old Etonian has gone from being Heineken – the politician who reaches the parts of the electorate other Tories cannot reach – to utter Marmite.

Play Video Princess Anne, Johnson, Trudeau and Macron appear to joke about Trump at Nato summit – video

Now he pursues a political strategy for a polarised country that deliberately seeks to divide it further by treating the other side as anti-national. You want Brexit, or you’re part of the remoaner elite. You want spending cuts, or you can bugger off to Venezuela. The critics are so busy fact-checking his fibs that there’s less time and energy to investigate the inconvenient truth. Crucial arguments about his eligibility for office are sacrificed instead for coverage of his latest gaffe. Policy loses out to political etiquette. Opponents in the media become mere accomplices. And so one of the most significant electoral choices of our lifetime is drained of consequence.

With his plans for a disastrously hard Brexit, his stated enthusiasm for tax cuts for the rich and his team schooled in the dark-money thinktanks of the transatlantic ultra rightwing, Johnson poses a serious threat to the British way of life. The details of the Whitehall-Washington trade talks released by Labour last week make that clear. Whatever the nervous denials from Trump and Johnson this week, everything from the food we eat to our rights at work to the state’s commitment to fight climate chaos spills across the boardroom table, ready to be bargained away.

Yet voters see not a danger, but a clown. Focus groups told the pollster Michael Ashcroft last month that Johnson would most probably spend a spare Friday night “shagging his secretary”. “There would be apologies the next morning.” Boys will be boys, especially those from the Bullingdon club.

There will be less laughter if he gets in. Look at the Institute for Fiscal Studies analysis of the Tory manifesto. Barely covered on the BBC or in the press, it gives the lie to those studio-sofa cliches about both parties “bidding to see who can spend the most”.

Instead, it calculates that a Johnson government will spend less, day to day, on everything outside the NHS – which is to say crucial things such as teachers or social security or care for the elderly, than 2010 levels – even as the fallout from his Brexit crash sucks jobs and money out of the private sector. A decade of cuts may have pushed your schools, your libraries, your councils to breaking point – but Johnson will ensure austerity carries on well into the next decade.

In their guide to this new age of autocracy, How Democracies Die, the Harvard political scientists Steven Levitsky and Daniel Ziblatt compile a checklist titled “Key indicators of authoritarian behavior”. Intended to illustrate Trump’s assault on democratic norms, it should serve as warning of how far Johnson may dismantle the UK’s own checks and balances.

“Do they reject the Constitution or express a willingness to violate it?” the checklist begins. And one recalls Johnson’s attempted prorogation of parliament that the supreme court ruled unlawful, and the ominous line in the Tory manifesto that pledges to “look at the broader aspects of our constitution”. Johnson’s withdrawal agreement grants him so-called Henry VIII powers to change laws after Brexit without needing to pass a fresh act of parliament. As a House of Lords report last month shows, workers’ rights and governance of Northern Ireland will be in his hands.

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“Do they baselessly suggest that their rivals are foreign agents?” Remember Johnson accusing Corbyn of “siding with the Russian spin machine” simply for wanting evidence over the Salisbury poisoning?

“Have they threatened to take legal or other punitive action against … the media?” After Channel 4 editors swapped no-show Johnson with an ice sculpture at last Thursday’s party leaders’ debate, No 10 threatened to review the broadcaster’s licence.

Were such things happening in another state, especially outside the west, our journalists would be quick to talk about autocracy. Urgent protests would pour forth from NGOs and politicians, perhaps including our prime minister. Inside our borders it is harder to find such clarity of perspective, yet the danger is visible. Johnson may be a rogue, but what should worry us is that he is a risk to our economy, society and democracy. His bad manners should not distract from the fact he is a bad man. Treat this election as some kind of joke, and we may laugh ourselves into plummy-voiced, perma-smirking, tousle-haired despotism.

• Aditya Chakrabortty is a Guardian columnist