Every post-mortem on the 2019 federal election campaign should open with a mea culpa. Mine is about the presidential twist in the contest. I underestimated how quickly Scott Morrison would learn from his mistakes as caretaker prime minister. He had made so many in his hurry to introduce himself to the Australian people that I wondered if they’d already written him off. Two own-goals stood out. The first was his proposal to move Australia’s embassy in Israel from Tel Aviv to Jerusalem in the final days of the Wentworth byelection last October. It didn’t save the seat; in fact, it contributed to the late swing to the independent, Kerryn Phelps. The second was his attempt to wedge Labor on border protection earlier this year. Opening Christmas Island, then closing it again and claiming the backflip as a budget saving would have made even the most rusted-on conservative wince.

What Morrison revealed in these moments was an Abbottesque lack of interest in process and policy logic. If he had continued down the dead end of look-at-me announcements, who knows if Queensland could have protected him from a southern revolt. But he stopped the indulgence just in time. Morrison parked his ego to make the election campaign a referendum on Bill Shorten. He did this by recasting himself as opposition leader of a non-existent party, and shifting the onus on to Shorten and his Labor team to defend their policies while wrestling an opponent made of smoke. The last part of the equation was the innovation. The absence of an agenda beyond generous unfunded tax cuts released Morrison from the obligation to answer even the simplest question from the media pack. While this shredded what little dignity was left in the prime minister’s office, it gave his government its best chance for a miracle.

The Coalition entered the campaign in minority, with 73 seats against Labor’s 72 in an enlarged parliament of 151. Morrison helped put them there with the loss of Malcolm Turnbull’s seat of Wentworth. A further two seats had moved to Labor’s column in Victoria following the redistribution of electoral boundaries that reflected Melbourne’s status as our fastest growing city.

The path back to majority for the Coalition required a net gain of three seats. Morrison got four: two in Queensland and two in Tasmania. All were in the regions. And so a government that had effectively sacked itself by removing two prime ministers won a third term. No penalty for the conservative civil war and policy paralysis; no prizes for Labor’s ambitious program of taxation reform and social spending. This was the status quo election no one saw coming.

But beneath the headlines of Morrison the Messiah, Labor’s complacent Victoria-centric campaign and the failure of the opinion polls, both public and party, to pick the result, is a nation permanently divided.

We have seen this election twice before this decade: the hung parliament of 2010 and the Turnbull government’s one-seat majority in 2016. The same faultlines between young and old, and between the cities and the regions, were exposed each time.

In each of the three campaigns, the Coalition was led by a Sydneysider and Labor by a Melburnian. Each time Labor won a majority of seats across the two most populous and two least populous states, and the two territories; an electoral alliance that would have secured majority government in any other decade of federation. But the two frontier states pulled rank each time. Between them, Queensland and Western Australia account for just under a third of all the seats in the federal parliament. But the super-majorities they delivered to the Coalition were enough to erase the majority that Labor enjoyed everywhere else.

If last month’s election had simply been a contest for NSW and Victoria with the ACT thrown in for good measure, a constituency representing more than half the nation, Labor would have governed comfortably with 48 seats against the Coalition’s 37, and a crossbench of three. Add the two poorest states, South Australia and Tasmania, and the Northern Territory, and the Labor advantage over the Coalition extends to 14 seats – 57 versus 43 with a crossbench of five. More than two-thirds of the country – 105 of the 151 seats in the federal parliament – is covered here.

But Labor went backwards because the other third of the country was overwhelmingly conservative. Here’s the catch, which was lost in the binary election takes of Morrison’s marketing genius and Shorten’s big target blunder. In the 21 seats across Brisbane and Perth, the Coalition won 11 and Labor 10. But the Coalition’s super-majority in Queensland and Western Australia was built outside the capitals. The Liberal National Party won 18 of the 20 seats in regional Queensland, and the Liberals won all five in regional Western Australia. The sole Labor seat outside Brisbane is Blair, based around Ipswich, in what was once Pauline Hanson territory. The only other regional Queensland seat that the Coalition didn’t win was Bob Katter’s Kennedy.

And so the 13-seat advantage Labor enjoyed over the Coalition across eight capitals, four states and two territories was erased by a 22-seat landslide to the Coalition in the regions of just two states.

In congratulating Morrison on the Coalition’s re-election, Donald Trump compared the result to his own and to Brexit in 2016. Of course he would. But the main parties here would be missing the point if they reached for an American or even a British analogy. Our politics fractured first, in 2010. That election had both the superficial and the structural elements of the US presidential contest six years later. An angry conservative male pretending to be anti-establishment versus a progressive woman cast as a nation-wrecker.

The contest between Julia Gillard’s Labor government and Tony Abbott’s opposition was the first election to be disrupted by the internet. One in 10 voters followed the campaign through new media in 2010. The print mastheads were unable, or unwilling, to prioritise the scrutiny of policy, while commercial television stopped pretending and covered the campaign as a soap opera.

The parties told themselves that Australians would never hang another parliament after the experience of the Gillard minority government. But the restoration of majority government under Abbott in 2013 proved more divisive still. That government effectively died on May 13, 2014, when treasurer Joe Hockey delivered its first budget. Where did Abbott and his ministers get the idea that Australians wanted to end universal healthcare, leave young people without the dole for six months, or slash $80 billion in funding to the states for schools and hospitals over the following 10 years? The cutbacks punished the very people whose resentments Abbott had harvested to block action on climate change. The Senate did the government a favour by rejecting the nastiest elements of the budget, but at the expense of sound public policy. After picking the wrong target for savings, the Coalition basically gave up after that.

The next two Liberal prime ministers, Turnbull and Morrison, allowed government spending to creep up as a share of the economy, and government debt to double in dollar terms. This remains the most telling statistic of conservative rule to date. The Coalition has spent more than Labor, even though the Rudd and Gillard governments had been saddled with the global financial crisis. Government expenditure as a share of the economy averaged 25.1 per cent per year between 2013–14 and 2018–19. Labor’s record was 24.8 per cent per year between 2008–9 and 2012–13, a difference of almost $5 billion in today’s terms.

Labor people won’t like the comparison, but the party’s 2019 platform contained an element of Abbottesque hubris. The policy to curb franking credits became a symbol that Labor wanted to punish older Australians. The very people who swung against Turnbull in 2016 feared that a Shorten government would come after them. Sure, the Coalition made stuff up about death taxes. But what did Labor expect after the success of its Mediscare campaign against Turnbull?

Every election this decade has had, as its central element, a complaint about the cost of living. Rising electricity prices shaped the 2010 and 2013 campaigns; the squeeze on real wages influenced the 2016 and 2019 campaigns. The party demanding a sacrifice in the national interest proved to be a soft target. And when the parties identify tribally – Labor with younger cosmopolitan voters, the Coalition with older voters in the regions – it is easy to paint the other side’s agenda as a personal attack on your identity.

Labor will no doubt overthink its loss and settle on a smaller-target strategy next time. But the lesson of the past decade is more nuanced. Voters are still prepared to give things up, provided they can see a direct benefit. It is the difference between curbs on negative gearing, which won support from both younger and older voters, and the capping of franking credits, which frightened older voters without share portfolios.

The bigger lesson of 2019 is that Labor cannot rely on demography even though it leans centre-left. This is the paradox of Shorten’s big-target, small-base strategy. Labor thought it had more paths to victory because there were so many more Coalition seats with tiny margins in Melbourne, Perth and Brisbane, and to a lesser extent Sydney. It did not see the resentment a capitals-first approach would create in the fringes of the cities and in the regions. But let’s assume it worked. Labor’s metropolitan majority would have been no more unifying for the nation than the Coalition’s Queensland-first gamble.

In the end, both sides were playing with the fire of polarisation because they lacked the imagination to bridge the divide between new and old Australia. Labor lost a winnable election because it couldn’t expand its majority in Victoria. The Coalition restored its governing majority thanks to a blowout in Queensland.

The Australian Electoral Commission sorts the political map 55/45 between the cities and the regions. Of the 82 seats in the capitals, Labor won 49 and the Liberals 30. Of the 69 in the regions, the Coalition won 47 and Labor just 19. In each zone there were three independents.

This schism is literally between taxpayers and welfare recipients, between the young workers in the cities and the retirees and underemployed in the regions. In this world, neither party can claim a legitimate mandate if it asks voters to simply choose a tribe.

I am wary of making predictions at the start of a new parliamentary term. But the weight of political history is against Morrison and the Coalition. A victory against the odds, and on the basis of a massive scare campaign, usually leads to a wipe out the next time. In 1980, Malcolm Fraser accused Labor of wanting to tax the family home. In 1993, Paul Keating campaigned against the goods and services tax, which he had previously supported as treasurer. In 2004, John Howard said interest rates would always be higher under Labor. In each case, the prime minister need not have gone as hard because the public had reservations about the alternatives: Bill Hayden, John Hewson and Mark Latham.

It is Keating’s post-election experience that offers the clearest warning to Morrison. Keating had run on the promise of unfunded tax cuts. He chose this approach to isolate the nasties in Hewson’s “Fightback!” package. But the budget was still in deficit after the recession. Keating hoped that bracket creep would eventually pay for his tax cuts. This is precisely the formula that Morrison relied on to get through the 2019 election. Take the best case scenario for the budget, load tax cuts on top of it and pray for no post-election surprises.

Keating didn’t get away with it. The first Labor budget after the election delayed one half of his “L-A-W law” tax cuts and paid for the other half by increasing indirect taxes.

Whether Morrison is forced into drastic budget repair remains to be seen. But he has assumed power in his own right on the worst possible premise: that voters can have something for nothing. With the global economy slowing, and the cost of dealing with climate escalating, Scott Morrison will soon be forced to ask a nation he helped divide to make a sacrifice for the greater good.