Prime Minister Malcolm Turnbull might come to rue not calling an election sooner. Credit:Daniel Munoz SPOILER ALERT: King reckons not. Jake saves JFK, but then goes back to the future to find the United States a blasted wasteland. The butterfly flapped its wings in 1963 and 2011 became a nuclear nightmare. All of which is to say that even if we could turn back time, it might not have the consequences we predicted or hoped for. But what-if scenarios are undeniably fun. Like this old chestnut: what if Kevin Rudd had called a double-dissolution election in early 2010? He had the perfect reason: the Parliament was refusing to pass his emissions trading scheme, the centrepiece of his plan to tackle climate change, which he believed to be "the greatest moral challenge of our time".

Illustration: Matt Davidson He had a mandate for climate action, his personal popularity was still strong, and no one took Tony Abbott seriously. Had Rudd gone to an early election, there's every chance he would have won comfortably. But he hesitated. He shelved the ETS, shredding his credibility. His support plummeted and his colleagues tore him down. Illustration: Michael Mucci A Rudd victory in 2010 would have changed everything; it would have cemented his authority and he might still be in office today.

OK, maybe not – his colleagues hated him and may well have found another reason to remove him eventually. But think how different the political landscape would be: at the very least, the climate-change fight that still afflicts Australian politics would have been settled. Abbott may have gone the way of Brendan Nelson and Malcolm Turnbull before him, opposition leaders steamrolled by the Rudd juggernaut. Turnbull probably would have left Parliament, as he'd planned to. Labor may well have made an orderly transition from Rudd to Julia Gillard, who presumably would have done a much better job under more conventional circumstances. Or who knows – maybe Wyatt Roy or Clive Palmer or Ian Goodenough would be prime minister today. Or maybe the world would be a nuclear wasteland. But make no mistake, if Rudd could go back in time and make a different decision, he would – regardless of the risk of unintended consequences.

Now consider this: what if Turnbull had pulled the election trigger late last year? Because after yet another ragged week, he's probably wishing he could hop in a time machine and do just that. What if he had gone to the Australian people shortly after he replaced Abbott and said: "I don't want to govern without a mandate. I want your approval to take this government in a new direction." He surely saw Gillard's experience as a cautionary tale – a woeful campaign that resulted in a hung Parliament that drove the nation nuts. But it wouldn't have panned out like that for Turnbull. After the past three months – marked mainly by scandal, policy paralysis, the tax debate mess and the ghost of Abbott past – the PM's honeymoon feels like a distant memory. But in 2015, his approval ratings were stratospheric and it increasingly looks as if he should have capitalised and gone to the polls then.

There would have been some practical hurdles, sure; most notably, coming up with an election platform that differentiated him from Abbott without sending the right-wing attack dogs completely crazy. But think of the advantages. He could have gone to the people before his numbers – both personal and party – started to slide; before voters realised their expectations were unrealistic; before the attacks on his weak-kneed approach to same-sex marriage and climate change and republicanism started to bite; before the Mal Brough, Jamie Briggs, Stuart Robert and Arthur Sinodinos affairs; before the conservative cabal started feeling emboldened; and before Abbott started making real trouble. He could have avoided the tax debate, which seems to have done little but hand his opponents ammunition. He could also have avoided the Herculean task of crafting an election-year budget with no money. Even if October or November 2015 had proven too difficult, March this year was surely doable. Yes, the honeymoon was over by then and government had started looking wobbly, but it still would have won comfortably. And yes, despite some recent 50/50 polls, the election is still Turnbull's to lose. His personal numbers are still much stronger than Bill Shorten's and Labor just has too many seats to win to form government.

But the trajectory is not good. Turnbull and Treasurer Scott Morrison have to deliver a good budget, which will be bloody difficult – particularly given it looks like they've lost each other's phone numbers. Turnbull will be hoping he gets his double-dissolution trigger for July 2, because if he has to govern for another six months and it's anything like the past three, he might find himself harbouring the same regrets as Rudd. Adam Gartrell is national political correspondent.