Nothing in his life became him like the leaving it. It was chaotic. Boris Johnson’s last hours in office were palpably staged, not to ease his party’s torrid history or respect the dignity of his office. They were fashioned as the opening chapter of his memoirs: “How the bastards tried to oust me.” It has been Boris in full flow, two fingers to his colleagues, rhubarb to parliament and to politics in general, bombastic towards his critics to the last on the steps of Downing Street: “When the herd moves, it moves.” It has all been a cynical game, a singing, dancing music-hall turn. Despite Johnson’s declared intention to continue until a successor is chosen, it is hard to see how that is possible given the manner of his departure. Many of the senior officers of state have resigned, been sacked or indicated no faith in him. Some departments such as housing and education are scrambling after a disconcerting period of having no ministers at all. Government is a team effort and requires order and leadership. It has disintegrated. Today it was clear Johnson simply cannot continue any longer and should be replaced by a stand-in deputy. Downing Street has seen no shortage of egotists, from Disraeli and Lloyd George to Churchill and Eden. But behind the mirrors have been executive prime ministers of substance. Behind Johnson’s mirrors are more mirrors. Each act in his political career has seen an ideological emptiness filled with self-promotion. The abuse of power has been total, from favours for lovers to contracts for friends. He has abused everything from the honours system to international law. Even his erstwhile profession, journalism, has almost universally called for him to go. The case for the defence should be heard. Johnson’s public persona has been undeniably likable to some. As mayor of London and then as Tory leader, he converted charisma into electoral gain, from working-class and former Labour voters as few Tories have done. He did so not through policy but despite a privileged background by appearing as a regular if unserious individual, a so-called “authentic” whose presence made those around him smile. He lightened an often wooden political mood, turned sour by a (by then) grumpy and habitually divisive Ken Livingstone. He turned sunny politics into a potent weapon; no mean feat. Charm is a quality whose potency is much underrated in British politics. As such, Johnson in 2019 rescued his party from the doldrums into which a succession of mediocre leaders had driven it, propped up by Labour’s inability to fashion a remotely plausible claim to power. He had been an acceptable London mayor and as leader was able to convert a modest 300,000 advance on Theresa May’s Tory vote into a Commons majority of 80, much of it in “red wall” territory. A seismic political shift beckoned, casting the Tories as a party of poor northerners against Labour of the graduate southerners. On that shift, only time will tell. History will find it hard to disentangle the Johnson era – or rather episode – from the exceptional circumstances in which it occurred. An upheaval in the nation’s trading economy, a global pandemic, a war in eastern Europe and an inflationary crisis would have tested any nation’s leadership. Though flustered and indecisive, what we know of Johnson’s pandemic does not seem appreciably worse than that elsewhere in Europe and was later rescued by the enterprise of Britain’s vaccine scientists. Johnson’s hijacking of Ukraine’s defiance of Moscow was outrageous if understandable, and the war was hardly his fault, any more than was the savage backlash from sanctions. As for the soaring cost of living, he has seemed no more or less at sea than the bankers, pundits and his own chancellor. The reality is that Johnson’s failings were personal rather than political. He could never handle rivals near him, and his dismissal of May’s abler ministers deprived him, and the UK, of experience and ability in favour of second-rate acolytes. As for the depiction of Downing Street that emerged from Partygate, it was of a bunch of squatters taking over a national treasure. It genuinely shocked the country. The historian Anthony Seldon has argued that the premiership is the “lived experience” of a particular individual. That experience must respect Westminster or the chemistry will simply reject it. Johnson has been instinctively presidential in style, with daily photo opportunities and cabinet meetings broadcast on television. His apparent contempt for parliament, his absurd peerages, his casual treatment of sexual misbehaviour, his simple inability to be open with the truth, all defied his celebrated “authenticity”. They made him seem devious and corrupt. Just as no one should underrate the qualities that brought Johnson to prominence, so no one should underrate those that have brought his downfall. It is easy to talk down the current generation of British politicians but they have lived and worked through a uniquely difficult decade, with uncertain leadership on both sides of the House of Commons. It is perhaps the price paid by constitutional monarchies, though the US is passing through an agony of presidential course correction. Britain’s political leadership is once again in doubt, in the case of Labour through the inexcusable delay in a Durham police investigation of Keir Starmer. But the parliamentary system has delivered as it should. While voters may be sovereign every five years, the majority party’s duty is to interpret the voters’ choice. That includes its own judgment of who should run the country. The trial has been messy but the sullen ranks of jurors on the Tory benches on Wednesday said it all. Johnson’s herd did move. The Conservative party’s verdict has been emphatic and its sentence swift. But its record of five leaders in 20 years is not good. The country awaits the next with trepidation. Simon Jenkins is a Guardian columnist