John Hewson managed it back in 1993, and it proved a terminal blow to his authority, not to mention setting the ‘big target’ political strategy back so far that it still hasn’t really recovered.

And, of course, Steven Marshall pulled it off four years ago, although he was largely absolved because by the end the 2014 state poll resembled less an election than some long-lost Franz Kafka novel, and because there was no-one else who could credibly lead the party anyway.

Since we mention Hewson, it’s now a matter of political folklore that his campaign was derailed because he put out detailed policy far too early, allowing Paul Keating to tear it to shreds. Which is one reason why, these days, we rarely hear a peep about policy from Oppositions, almost until you’re literally walking into a polling booth and they’re running up to you trying to explain their detailed four-year plan.

And, to be fair, I can see where they’re coming from.

Let’s take last weekend as an example.

Among other bits and pieces, the Labor Party unveiled three election pledges: it will, it says, spend $200,000 at local surf life-saving clubs “to trial new shark surveillance and deterrence technology”, including, of course, drones. It will appoint an Aboriginal children’s commissioner. And it will build a new park ‘n’ ride for 350 vehicles at Paradise interchange.

Now, it may just be déjà vu, but all this sounds kinda familiar.

Possibly because the Libs already promised to fit out each of the state’s surf lifesaving clubs with a drone in a $200,000 pledge back in November.

And then in December, they said a Liberal Government would establish an “Assistant Commissioner for Aboriginal Children”.

And, of course, in January they pledged a $7.5 million park ‘n’ ride to add more than 300 parking spaces at Paradise interchange.

Which means Labor’s new campaign slogan should probably be: “Anything you can do, we can do too.”

Or, given they’ve chucked in an extra $12 mil for various other infrastructure goodies: “Anything you can do, we can do better.” Or at least more expensively.

It shouldn’t be forgotten, of course, that they already pledged the park ’n’ ride at the last election, only to ditch it once their late-unlamented carpark tax hit the wall, a move they probably didn’t ponder much at the time since the relevant seat of Hartley had recently fallen the Liberals’ way and was unlikely to swing back to Labor anytime soon.

Except.

Along comes a local resident named Mr N. Xenophon, and Labor, it appears, has had a change of Hartley.

All of a sudden, they’re all too keen to spend buckets of cash in this Liberal marginal.

Transparently cynical? Sure.

But if the Libs have a right to feel enraged that Labor is systematically adopting their entire program, their weekend utterances hardly show it.

Indeed, the first retort to Labor’s announcement from the SA Liberal Media Twitter handle – as ever, more phlegm than phlegmatic – was a crack at Nick Xenophon:

Once again @Nick_Xenophon providing commentary about other parties plans, this time regarding the Paradise park n ride. Nick Xenophon's SA-Best don't even pretend to have their own plans to create jobs, lower costs or deliver better services #saparli

— SA Liberal Media (@SALibMedia) February 11, 2018

It was a similar scenario when Labor evidently ripped off another Liberal pledge, to roll out a phonics check across SA schools, to which shadow education minister John Gardner himself responded with – you guessed it – a crack at the SA Best leader:

I am genuinely pleased to see that Labor has now matched @marshall_steven Liberal policy to deliver the Phonics Check across SA. Now can someone let Nick Xenophon know that the trial he suggests in his new Education policy actually took place last year so he can catch up too? pic.twitter.com/OUXU33fPp8

— John Gardner MP (@JohnGardnerMP) February 10, 2018

It’s not really the done thing to reference Tarantino these days, but it’s kinda like the end of Reservoir Dogs – one guy fires a shot at another guy, who responds by shooting a different guy standing nearby. The net result: everyone gets hurt.

If nothing else, it’s a sign of how the traditional battlelines have been frayed by SA Best’s emergence.

It’s likely neither Labor nor the Libs would have bothered spending the sort of cash they’re throwing about in Hartley were it not for Xenophon – the seat would have been pencilled in as a ‘Liberal-retain’, and everyone would have gone about their business accordingly.

But it’s not just Hartley cashing in.

Last week, SA Best pledged to ensure the Penola bypass would be completed if it held the balance of power, a $4.5 million commitment in the nominally safe Liberal seat of MacKillop. Marshall had visited the electorate himself in December and hadn’t committed to funding the project – what a missed opportunity!

It’s possible, of course, that the Libs were planning to roll out their own commitment when they were good and ready, and were caught napping – but this election is, more than ever before, all about timing.

Go too early and you’ll see your agenda cynically appropriated and enhanced by one political opponent.

Go too late and another political opponent will steal a march – and possibly steal March.

But then, this whole campaign is genuinely ludicrous, with both Liberal and Labor camps feigning fiscal rigour, despite everyone knowing both will, naturally, squib their costings under the cover of that old chestnut – a public service “efficiency dividend”.

And Xenophon, meanwhile, is pretending to have actual across-the-board policy positions, as opposed to his more traditional feelpinions.

In many cases, he is literally putting out policies not because he thinks they are worthy ambitions for government, but because he’s worried that if he doesn’t people will say he doesn’t have any policies.

Which means the major parties have him rattled.

But it will inevitably expose his party’s ill-preparedness for government.

Last Friday, after the major parties seized on his long-awaited health policy to point out a $2.3 billion costing “black hole” – after the document quoted the health budget at $3.6 billion, rather than the budgeted $5.948 billion – Xenophon fessed up, telling TV cameras he’d rather underestimate the figure than overestimate it.

.@Nick_Xenophon has underestimated how much the government spends on health by almost $3 billion. https://t.co/kHJ2kbmrCp #saparli #7News pic.twitter.com/jXc9rHNAAJ

— 7NEWS Adelaide (@7NewsAdelaide) February 9, 2018

And yet, even as he was copping it on the chin, his sometime media manager and other-time Upper House candidate, former Today Tonight headkicker Frank Pangallo, was embarking on a tweet-storm, informing anyone who would listen – and yet more who wouldn’t – that the “black-hole” barney was yet more “fake news”, for which the media had fallen “hook, line and sinker”.

https://twitter.com/FrankPangallo/status/961857451661320193

The next morning, once the dust had settled – and the ship had sailed – Pangallo had evidently convinced at least one person – Xenophon himself – who duly went cold on his mea culpa, putting out a media statement calling the costings furore “nothing more than a shallow political diversion”.

Labor and Liberal, he said, “both know that $3.6 billion is the actual cost to the State Budget for running our health system – with an additional $2.3 billion coming from the Commonwealth and other sources of revenue”.

“The $3.6 billion is the net cost of the provision of services to the State Government to run the SA health system,” the clarification read.

“The total expenses for health and ageing – including from Commonwealth revenue, grants, fees and other sources – is $5.9 billion. SA Best’s policy document has been amended to clarify this point.”

At any rate, having to “clarify” policy documents after they have been released is hardly something that instils confidence, nor is the fact the document itself was evidently released some hours after it was originally intended, as SA Best’s brains trust fine-tuned aspects of the plan.

Still, Xenophon can – as ever – count himself lucky.

In the normal run of things, a $2 billion gaffe would be an electoral deal-breaker.

The major parties are, quite reasonably, working to this assumption. But Xenophon appears to operate in some political bizarro world, wherein a costings gaffe is broadly regarded as simply more evidence of his chaotic, flustered charm and the major parties pointing it out further proof that they are incorrigible bullies.

If the 2014 election aftermath was like a Kafka-esque hellscape, this campaign is more like some strange scene from Alice In Wonderland, wherein everyone involved must be mad or they wouldn’t have come, and it’s plausible to believe up to six impossible things before breakfast.

The phrase “No shit, Sherlock” was once coined as a retort to just the sort of people who are now running around shouting about how policy is not Nick Xenophon’s strong suit.

I mean, he’s literally almost never had to devise a policy per se.

His bag has always been as an advocate or adjudicator.

Why would he suddenly try to change a formula that’s served him so well for so long?

For someone who hates pokies, it’s a ridiculous – and needless – gamble.

If Xenophon has somehow, thus far, avoided being judged by the electorate according to the usual standards of political engagement, he should accordingly stop trying to run a traditional election campaign.

The more he tries to pretend he is an equal player to Labor and Liberal, the more this campaign ends up like the denouement of Animal Farm, wherein the voters look from major party duopoly to minor party interloper and back again and find it impossible to say which is which.

Instead, Xenophon would be far better off to say ‘we have no intention of governing this state, but merely to keep the governing party in check’ and offer not half-baked policies but explanations of how the machinery of government could function more smoothly with SA Best holding the balance of power.

And, if he was honest with himself and had the ability amid the maelstrom to stop and take stock for a mere moment, Xenophon himself would probably acknowledge that he doesn’t actually want to govern anyway.

His political history suggests someone with an aversion to tough decisions; like the career politicians from whom he has somehow managed to divorce himself, he loves to be loved. And, more fervently still, he hates to be hated.

Last year’s media reform legislation, for which Xenophon’s senate Teamsters held the deciding votes, is a case in point.

For Xenophon, the consummate media performer, it was a perfect storm: torn between the whims of the Federal Government, the interests of powerful media barons and the livelihoods of an army of journos, many of whom he had known personally for years.

I interviewed him on occasion throughout the deliberations, and he sounded exhausted, almost broken. I’ve always felt it was that ordeal, rather than the looming citizenship adjudication, that hastened his egress from Canberra.

What I don’t get is: what’s his endgame here?

Part of his political armoury, the thing that’s always underpinned his untouchable charisma, is that he has been a critic of the powers-that-be, not an enabler.

If this election marks the high watermark of the Xenophon phenomenon, it could also herald the start of a rapid decline. Whoever governs after March 17 – or thereafter – it will likely be at the behest of SA Best – who will therefore be held responsible by around half the population for installing a government they didn’t want.

Such was the fate of Karlene Maywald, the former Nationals MP and sometime Rann Government minister, who went from a 17 per cent margin in 2006 to losing her Chaffey stronghold just four years later. (This time round, incidentally, there’s every chance Chaffey will go SA Best’s way.)

But the closer polling day looms – and despite Steven Marshall’s conspiracy theories – the more the scenario that looms most plausibly becomes a hung parliament, with Xenophon supporting the Liberal Party to form government.

After all, one can hardly predicate an entire campaign on the need for change, and then opt for the status quo… can one?

But the Libs, with Marshall having already ruled out negotiating with Xenophon post-poll, would be hideously compromised under such an arrangement, and it wouldn’t take long before their hibernating tribal gripes are reawakened.

It’s arguable that there will be no real winners in this election: least of all the voters trying to make sense of it all.

But there could at least be some poetry in it.

Especially for Marshall, the man who lost the unloseable election – and could yet win the unwinnable one.

Even if he’s not around to savour the victory.

Tom Richardson is a senior reporter at InDaily.

Stay tuned for InDaily’s election podcast – The Unwinnable Election – which begins on Friday.