On 19 June, shortly before the EU referendum, David Cameron tweeted that 'Britain isn't a quitter.' Outside 10 Downing Street three days later, he reaffirmed that 'Brits don't quit.' The next day, Britain voted to quit the EU. During the campaign, he had let it be known that if it did, he would remain prime minister – before quitting on the morrow of the referendum. In his resignation speech he vowed to stay on until the autumn, to 'steady the ship' for his successor. When he was elbowed aside within a fortnight, he vowed not to quit as MP for Witney. Now he's quit at that, too.

In an emergency meeting with close confrères at No. 10 at about 3 a.m. on the morning of 24 June, when it had become clear that Brexit was looming, Cameron rehearsed Enoch Powell's dictum that all political lives end in failure (Powell qualified: 'unless they are cut off in midstream at a happy juncture', not a caveat that applies in this case). Some failures are bigger than others. Taking the state on a joy ride and crashing it, along with his sometime mates Michael Gove and Boris Johnson, must rank, along with Suez and Iraq, among the bigger ones.

Admittedly, the man whom Norman Tebbit once compared to Pol Pot has logged some successes, notably hauling his party back from the electoral boondocks. Against mostly mediocre opponents, Cameron blagged wins in the 2010 and 2015 general elections, as well as the alternative vote and Scottish independence referendums of 2011 and 2014. His luck ran out with the EU poll, but the luck itself largely consisted in his being spared blowback from his own lack of political judgment, a trait about which he unsurprisingly also showed a lack of judgment.

His government made more U-turns than a toilet factory. Often in cahoots with George Osborne, Cameron flip-flopped across the gamut of policy, including taxes on granny flats, tampons, solar panels and pasties, as well as on cuts to pension relief, personal independence payments and working families' tax credits. Latterly Cameron seems to have assumed, like many, that the referendum was in the bag. After last year's election win, I suggested that Cameron would succumb to the Promethean hubris that often overtakes premiers in their second term. Power coupled with robust self-belief (Cameron once said he thought he'd be 'rather good' as prime minister) slips easily into assuming that believing something can make it so. Hubris met comeuppance on 24 June.

Nowadays there are few second chapters in British political lives. Partly that is because failure is less tolerated. Ted Heath managed to lose three out of four elections before getting the heave-ho. Politics, no longer showbiz for ugly folk, now favours the young and telegenic, the slick over the non-vacuous. Burn-out comes early. So top politicos quit while relatively young (Cameron is not quite fifty) and hoover up directorships. Tony Blair's Stakhanovite post-premiership nest-feathering is well known. Margaret Thatcher bagged $1 million a year for advising the tobacco firm Philip Morris. Before he took over as Tory leader in 2005, Cameron had a part-time executive job with the pub chain firm Urbium; now he'll be able to spend more time with 'the causes that mean so much' to him, and his directorships. After today's boundary redrawing he has an intact constituency to bequeath to his successor, unlike Osborne or Jeremy Corbyn. Serving his Witney constituents, as he pledged to do on 24 June, lasted a couple of months, with two holidays thrown in.

He leaves a nation in limbo, certain neither of its own internal integrity or relation to the outside world, with a booming 0.00 per cent growth forecast for this quarter and the NHS facing a funding crisis. The final impression – the tsunami of the referendum result aside – is of a man without qualities, of one who leaves no final impression.