Australians need a new title for the politician who replaces a prime minister between elections. “Acting prime minister” or “caretaker prime minister”? Either would do to remind the government of the day that its new leader has not been tested at the ballot box. It would spare the media the pretence of deference, and might encourage future plotters to think before placing their government on the bonfire of public ridicule again.

Scott Morrison shouldn’t take this personally. As a keen student of politics, he would appreciate how each coup since 2010 was received by the voters. The first act of regicide sapped the authority of the government as it lost its buffer on the floor of the House of Representatives; the second opened the gates of electoral hell.

When Labor took its civil war into a second term, it did so understanding the risk of a wipe-out at the next election. But the players could not help themselves. It bears repeating that Labor’s primary vote in 2013 collapsed to 33.4 per cent – its lowest since the split of the 1930s. If the pattern repeats for the Liberal Party at the next election, it would threaten its very existence. The party of Robert Menzies has never lost office in a landslide before.

Knowing all this, the Liberals still leapt into the abyss in August. The insurgents did not have the numbers to remove Malcolm Turnbull for their preferred candidate, Peter Dutton. But they assumed their campaign could not fail because every prime minister since Bob Hawke who was challenged in the party room fell before the next election. The shocking thing, going into the second ballot, was that Turnbull could conceivably have survived until the end of that self-indulgent sitting week. As one Labor frontbencher remarked afterwards, that would have given Turnbull the nuclear option to call an early election. He might have had a mad chance of winning, this person conceded. Turnbull could have pitted himself against the extremes of Australian politics: Labor to his left, with their thuggish trade union connections, and the fanatics of his own party to his right.

And that has been the problem all along. The idea that a single individual could blow up the system to save it has become the great Australian delusion of the 21st century. The main parties have been on a self-sabotaging search for a messiah since 2007, when Labor surrendered its identity to Kevin Rudd to defeat John Howard.

Every successful federal coup since 2010 has involved a cycle of over-correction and acquiescence. The deposed leader was said to be crazy, or unpopular. The party room was reclaiming the government on behalf of the people. But then the new leader assumed the same authority as their predecessor, booby trapping the government for another coup.

The public view of these things has been consistent. Once a government removes its leader, it loses its mandate. It doesn’t matter how long the new prime minister waits to call an election; every coup since 2010 has been punished with a swing against the government.

On face value, the first-term executions of Kevin Rudd and Tony Abbott contained as many differences as similarities. Rudd was still popular; Abbott never was. Rudd was ousted without warning; Abbott had been given six months to improve his performance before he was finally challenged. Yet neither man saw their fall coming or accepted the verdict of their party room. Their respective crusades to reclaim their old jobs made the country ungovernable in the second term of each government.

It’s possible to imagine that Julia Gillard would have won a majority in her own right if the Rudd camp hadn’t leaked against her during the 2010 campaign, or that Turnbull would still be prime minister today if Abbott had been persuaded to leave the parliament at the last election in 2016. But what is more striking is that Gillard and Turnbull suffered almost identical swings. Labor lost 11 seats in total under Gillard in 2010; the Coalition lost 14 under Turnbull in 2016. The nation divided along the same parochial lines in each election. Labor was the majority party in the two most populous states and the two poorest – New South Wales, Victoria, South Australia and Tasmania – while the Coalition dominated in the mining states of Queensland and Western Australia.

The tribal composition of the Gillard and Turnbull governments meant that each was being tugged back to its base. Gillard’s minority government relied on the support of independents and Greens from New South Wales, Victoria and Tasmania.

Turnbull’s one-seat majority gave the attention seeker who threatened to cross the floor disproportionate power. Queensland’s George Christensen was considered the candidate most likely to bring down the government, and he even told Andrew Bolt and others he would move to the crossbench if Turnbull were still prime minister at the end of last year. But he remained a loyal member of the Coalition after Turnbull agreed to establish the banking royal commission. On this issue, at least, the conservatives found common cause with ordinary Australians. But then they reverted to type on the question of climate change.

It was Abbott’s threat to cross the floor against Turnbull’s National Energy Guarantee that reaffirmed how polarised politics had become within government. Even though the Coalition party room had approved the NEG, Turnbull did not want to risk bringing the legislation to the parliament because Abbott and others would likely have voted against it. Labor never entered Turnbull’s calculations. It was his negotiation with Rudd on the original Emissions Trading Scheme that triggered his downfall as Opposition leader in 2009.

But Prime Minister Turnbull was viewing the NEG from the wrong end of the telescope, and with the lens cap on. If he had asked Labor and the independents, they would likely have given him their support. The parliamentary vote would have been decisive. Yet Abbott had made bipartisanship a hanging offence, and, egged on by a handful of supporters in the media, he was able to bluff the prime minister into negotiating against himself. Turnbull began to roll back his policy to the point of incomprehension, which prompted Abbott to state the obvious: “What we want to know is, where are this prime minister’s convictions?”

The echo here was not Turnbull’s experience in December 2009, but Rudd’s in April 2010. Rudd’s leadership was doomed once he walked away from the great moral challenge of climate change.

The common thread through the two-party churn has been the implicit recognition that once a government splits there is no point pretending normal programming can resume for the remainder of the parliamentary term. The new leader is compromised until they face the people. The parties can’t have it both ways, conducting presidential campaigns and then insisting the public respects the will of the party room.

What is easily forgotten in the handover from elected to caretaker prime minister is the disruption caused by the new leader’s short-term agenda. Every change – from Rudd to Gillard to Rudd, and from Abbott to Turnbull to Morrison – has involved a bungled assertion of authority that has damaged Australia’s reputation.

Gillard made a mess of climate-change policy either side of the 2010 election. She assured voters there would be no carbon tax under the government she led, then promptly broke that promise as part of her agreement with the independents to form minority government. It is of no consolation that her legislation reduced emissions. The carbon price did not survive a change of government.

Rudd, by contrast, left a legacy of bipartisan cruelty. On the eve of the 2013 election, he closed the border to asylum seekers who arrived by boat. He said they would be transported to Papua New Guinea “for assessment and if found to be a refugee will be settled there”.

Rudd did not intend for Australia to become a global role model for xenophobia. He claims that he wanted to wind up the arrangement after a year. But the incoming Abbott government set the policy in stone, leaving thousands of refugees in limbo, and our allies divided between disgust and admiration.

Even Donald Trump thought it was harsh.

“Why haven’t you let them out? Why have you not let them into your society?” the newly elected US president asked Turnbull in their infamous telephone conversation in January 2017.

“It is not because they are bad people,” Turnbull explained. “It is because in order to stop people smugglers, we had to deprive them of the product. So we said, ‘If you try to come to Australia by boat, even if we think you are the best person in the world, even if you are a Nobel Prize–winning genius, we will not let you in.’”

“That is a good idea,” Trump agreed. “We should do that too. You are worse than I am.”

Turnbull proved to be the exception to the rule of excessive decision-making. He toyed with the idea of tax reform, but decided against it when he realised that any change to the GST would not yield the bounty for personal tax cuts he hoped for. Most of the money would have to be given back as compensation to low-income earners. He also outsourced marriage equality to a postal survey.

When Turnbull challenged Abbott in September 2015, there was an understandable temptation by many of us in the commentary class to declare an end to the Rudd-Gillard-Abbott era. Unlike Gillard, Turnbull explained the reasons for the leadership challenge, and promised to restore orderly cabinet government. No more slogans, captain’s calls or culture wars. But he waited too long to call an election, then indulged in an eight-week campaign that favoured Labor’s grassroots operation. The history he repeated was Rudd’s, twice. It was Rudd’s refusal to call a double dissolution election after the Senate rejected his climate change policy that undermined his leadership the first time. On his return in June 2013 he should have called a snap election. But he hesitated once more, and entered the campaign after his honeymoon period had ended.

The lesson each time is that the caretaker prime minister is best served by going straight to the people. But Morrison can’t do this, of course, because the Coalition would lose. He wants to give voters time to get to know him better. He will fling new ideas at them, while avoiding big issues such as climate change because he does not have the standing within the party to resolve its ideological feud. He will pick predictable fights with Labor over trade union power. He will confuse his personal obsessions with those of the people. He will be tempted to wait until next May’s budget, when he hopes a surplus can finally be delivered, before calling an election.

What happens if the electorate has already written off this government? Another coup seems ridiculous so soon after the last one. But Labor does provide a precedent for three leaders in a single term.

Both sides recognise that the madness of the past decade originated in New South Wales, in the final term of the state Labor government between 2007 and 2011. Premier Morris Iemma had steered Labor to an unexpected victory, but a year into the new term the party split on privatisation policy and he was ousted in September 2008. The government never recovered. His successor, Nathan Rees, held on for 15 months before Kristina Keneally replaced him in December 2009.

If Morrison can’t unite his riven government between now and the next election, Julie Bishop might be the first woman standing on the Liberal side. That would complete the farce.