The brutal political reality is that, today, the playmaker in British politics is indisputably the Tory party. It has always had crucial advantages: it is as much an open tribe based on class, social status and culture as a political party. It has the slavish support of a partisan rightwing press. Its ideas may be in the electoral minority, but a divided opposition and a first-past-the-post system confer election victory after victory. It has an appetite for power shared globally only with the Chinese Communist party. Now, led by Boris Johnson, it is once again master of all it surveys.

Its weakness is that with no fixed set of beliefs it regularly becomes transfixed by an ill-judged ideology – first Thatcherism and now Europhobia. The combination has led to its transformation, over the past 40 years, from a pro-European party to an anti-European one – both the precondition and ultimate cause of Brexit. The conversion is now complete. But the hard Brexit, to which it and its triumphant leader are wedded, might lead to its eventual undoing.

That may seem improbable now. There may be a progressive, if small, pro-EU majority in the country, as revealed by opinion polls and the results of the last election, when the Leave parties achieved only a minority of the vote. But Remain is politically divided, has no political leadership and no effective political expression in the House of Commons – catastrophic political facts for which Jeremy Corbyn and the cruel logic of the voting system are largely to blame. As long as Johnson can keep his party together and avoid disastrous missteps, his position seems unassailable for years. But just as Thatcherism finally did for the Tories in the 1990s, so hard Brexit will do for them in the 2020s.

The decision to hold a cabinet meeting in leave-voting Sunderland was symbolically smart

So far, Johnson is playing his poor cards well. He is certainly not the gaffe-prone, quasi-Thatcherite prime minister that his critics on the left expected. He is careful not to be too triumphalist about Brexit, knowing its toxicity. Instead, there is lots of upbeat talk about launching a national revival. The decision to hold a cabinet meeting on Brexit day in leave-voting Sunderland was symbolically smart. The language about the government’s mission to “level up” Britain’s spatially divided economy is also smart – positioning the government as less conventionally rightwing, more the champion of an activist state. Whatever else, this first phase of Brexit is not completing the Thatcherite revolution, as Lord Lawson trumpeted in 2016.

There have been a string of decisions that confirm Johnson’s description of himself as a “Brexity Hezza”. First, there was the bailout of the struggling airline Flybe, and last week ailing Northern rail was nationalised, with South Western Railway expected to follow. More importantly, the entire privatised system of competing for seven-year-long rail franchises is being reviewed, to be scrapped later this year. Instead, rail services will be run directly either by central government subcontracting the operation of major lines to rail companies on performance contracts, or by local government on the Transport for London or Transport for Greater Manchester model.

This is a de facto public ownership and management of the rail network – a variant of what Corbyn and John McDonnell planned, but much cheaper – and done with opportunistic chutzpah. Johnson knows privatised rail companies are unpopular and public ownership popular. He also knows from his experience as London mayor that Transport for London works. Ideological objections are put to one side: there is, in this reckoning, no “conservative” way of doing things, only an aggressive pursuit of popularity and ideology-free effectiveness.

Thus it will be no surprise if this week the loud hints are confirmed and Johnson goes ahead with HS2 – as he seemed to say on Friday to 10-year-old reporter Braydon Brent on Sky’s children’s news show FYI, a happier format for the prime minister than one in which he is challenged by adults. To announce its partial or even complete cancellation the week after Brexit, given the promises of levelling up, is a political impossibility – not to mention the forbidding £12bn cancellation cost.

Objections from senior advisers, notably Dominic Cummings, and MPs through whose constituencies the route will run, are to be brushed aside. Yes, he will talk of grave mismanagement, saving money and maybe reshaping the project – but it will get the green light. He has been influenced by the Treasury recognition that, given the sunk costs, there is no cheaper way of creating vital extra north-south rail capacity. Influenced, too, by the pressure from his newly elected MPs in the Midlands and north not to concede to southern nimbyism, northern voters must be kept onside.

The decision on Huawei was no less pragmatic and adroit. A swathe of Tory MPs may share Trump’s view that Huawei is an arm of the Chinese state – but Britain’s position, as one of the countries best prepared for 5G, demands access to Huawei’s antennae and other hardware, which are years ahead of any competitor. Capping Huawei’s usage at 35% – along with welcoming Trump’s absurdly pro-Israeli peace plan – allowed Johnson to square the circle. He kept the US on board, and sustained Britain’s emergent dominant 5G position.

Here, Cummings won a victory. His passion, he says, is to propel Britain to the forefront of science and technology. There is no option but to buy Huawei’s kit. Equally, the word is that he is being a formidable lobbyist in the March budget for “2.4” – that is, the commitment to progressively raise research and development spending to 2.4% of GDP, on which the Treasury is already wanting to backslide. Be sure the first downpayment will be made.

Britain is plainly not going to grow at 'new dawn' rates of up to 2.8%, as our curiously naive chancellor wants

Cummings was also behind last week’s removal of the issuance of visas for scientists and academics from the Home Office. Instead, the liberal open-door academic visa policy has been located within the UK Research and Innovation funding agency, which is charged with promoting Britain’s science base. It was a small, non-ideological masterstroke. Britain’s universities and companies alike are now assured of the overseas scientists they need from anywhere in the world.

However, Johnson has one fatal weakness – the Faustian bargain he struck to deliver a hard Brexit to win the prime ministership. Any economic bounce this year will be short-lived: the Bank of England’s forecast of 1.1% growth for the next three years could even be optimistic, as both inward direct investment and UK business investment dry up when access to the EU single market and customs union ceases. The Canada-style trade deal Johnson advocates is as close to self-immolation as economics provides. Britain already has a vast trade deficit in goods that will widen alarmingly as competitive overseas exporters take advantage of zero tariffs, while services – where Britain has great competitive strengths – will be crippled by being denied their former EU markets. It is insane and risks an unstoppable run on the pound, as a former cabinet minister privately agreed. Renewed austerity and recession will follow.

Johnson and his Brexit cabinet, backed by our Europhobic rightwing press, will blame dastardly Europeans for the crisis – and the anti-foreigner mood will grow ugly. But even if the worst is avoided, Britain is plainly not going to grow at “new dawn” rates of up to 2.8%, as our curiously naive chancellor wants. Rather, the years ahead are going to be a drip of disappointments, as the reality of a hard Brexit bites. And on this Johnson cannot be breezily opportunistic and convert to a soft Brexit, tempted though he may be. He will be imprisoned by his know-nothing right – the European Research Group in full battle cry.

Here is the opportunity for a revived Labour opposition, if only it can accept that the party’s future lies in championing the liberal pro-EU forces in Britain’s metropolitan cities and university towns, rather than just hankering after a working-class “base”. It needs a leader and a shadow cabinet holding Johnson to account for every Brexit-induced piece of bad news, and one that insists that economic stagnation, fiscal austerity, division and decline are the result of being too far from Europe – and that the solution is to get closer.

Johnson may want Brexit expunged from the public discourse, but the Remain/Leave divide is too deeply rooted for that. The only stable, long-run settlement should not be on the terms of the declining parts of Britain. Johnson and Tory strategists know that and worry about the Tories’ lack of appeal to the young. He needs to break his Faustian bargain, but his Mephistophelean right will make it impossible. Europe has broken all his predecessors since Thatcher. Eventually, for all Johnson’s adroitness and opportunism, it will break him too.

• Will Hutton is an Observer columnist