Ahead of make-or-break political contests, it pays to be cautious when political operatives materialise bearing internal party polling. Often these sorties are exercises in massaging voter expectations or manufacturing impressions to influence an outcome.

Having declared the necessary note of caution, let’s work through the known knowns about the contest everyone is currently watching: Scott Morrison’s battle to hold Malcolm Turnbull’s former seat of Wentworth in Sydney’s eastern suburbs, and the government’s majority in the lower house.

Liberals were talking among themselves last weekend about internal research showing the high-profile independent Kerryn Phelps was ahead of the government candidate Dave Sharma 55% to 45% on the two-party preferred measure. That polling turned up in the Australian mid-week.

The gloomy-sounding research found its way into the public domain shortly after Scott Morrison decided to telegraph the prospect of Australia going full Trump on our policy on the Middle East. The poll insight provided some context for the day’s extraordinary events.

In case you missed it, the prime minister countenanced the possible relocation of our embassy to Jerusalem on Tuesday, after having received advice the day before about the security implications of his kite flying – secret advice revealed by Guardian Australia this week.

Morrison’s announcement was targeted at the Jewish community in Wentworth. The government made that obvious by leaking the putative shift on Monday night to the two Sydney newspapers: the Sydney Morning Herald and the Daily Telegraph. The Australian was briefed too, but that’s compulsory in the rules of engagement in Canberra, because tantrums are the inevitable consequence if the Murdoch national broadsheet ever finds itself surprised.

So let’s put these events together and see what picture emerges. Party research in circulation last weekend suggests Wentworth is lost to the government, and by Tuesday, Morrison is micro-targeting Jewish voters in Wentworth in the hope that a burst of shock and awe might turn the tide, and the government might somehow emerge from its self-created mess with its majority intact.

The circumstantial evidence points to deep anxiety inside the government, with the seat-of-the-pants Israel sortie a more reliable barometer of that in my view than the leaked research, which I still suspect is about persuading deeply cranky Liberals not to lodge the protest vote they will want to lodge on Saturday.

People I trust insist the Liberal party’s current status in Wentworth is IDS – in deep shit. One person not prone to hysteria says the seat is lost. Another says the probability of losing on Saturday night is in the order of 75%. Another says it’s very tough.

We’ll all see soon enough, of course, whether this pessimism is well founded or confected to try to pull back the defections. We’ll see if the Liberals lose a seat they currently hold with a 17% margin, and whether the victor is Phelps or the Labor man, Tim Murray, streaking up the middle, despite the eleventh-hour efforts by progressive forces to hit the brakes on that prospect to try to clear the path for the independent who would have more hope of holding the seat at a general election.

Whatever the end result, we can pity the Liberal candidate, Dave Sharma. We can pity him because the government has delivered him nothing but trouble during the final fortnight of his campaign – a stream of leaks, own goals and administrative process failures – and that’s got to be tough for the guy fronting up on the hustings every day.

But there’s a deeper level on which we can take pity on the candidate. Just consider the central absurdity of the Liberal party’s campaign pitch in Wentworth: vote one, Liberal, for stability.

I’m sorry, but in what universe is a vote for the Liberals a vote for stability? Lest this observation seem gratuitous, let’s do a quick recap. It’s tough to keep this to three points, but I will.

One. The Liberals have given Australians three prime ministers during two terms in office. Sadly for the government, and for the rest of us, the two terms in office have been characterised more by vicious civil warfare between the government’s moderate and conservative factions than by signature policy achievements. These folks struggle to agree on things, and default on a hair trigger to death match.

Two. The Nationals lost their leader in circumstances now so well known we can avoid the recap. Not content with round one, Barnaby Joyce is now positioning himself for a comeback because in Australia’s unhinged, ego-soaked political culture, apparently you only need serve a few months’ penance for a significant breach of public trust before you can pop yourself back on the travelator for advancement: because enough about you, the voters, more about me.

Three. Eight weeks ago, the country was treated to the spectacle of conservatives tearing down Turnbull. The publicly funded revenge tragedy was spearheaded predominantly by the bloke who Turnbull tore down in 2015, Tony Abbott, and some fellow travellers – and the blood letting was so brutal several members of the government couldn’t contain their despair. Actions, of course, have consequences. Before the knives came out Turnbull issued a public warning that he would quit the parliament, pronto, in the event he was cut down from the prime ministership. Turnbull could not have been clearer about his intentions, yet they cut him down anyway, despite their own collective vulnerability with their one-seat parliamentary majority. That burst of nihilism is why we are having the byelection on Saturday: with poor old Dave Sharma out loyally mouthing his talking point, vote for us because #stability.

It really is beyond parody.

If Sharma does lose on Saturday night, the Coalition goes into minority government.

At the moment, around the government, senior figures talk a lot about the runway. Scott needs more runway. We can bring this contest back if we can only extend the runway. If you are confused about the runway, it just means more time to accelerate before take off.

We need more runway has become the unofficial mantra.

Minority government will shorten the runway, because a blow in Wentworth will ricochet back inside the Coalition, prompting more ill-discipline, which makes the operation more difficult for Morrison to manage, which projects a lack of competence to the voters, so the negative cycle feeds itself.

To cut a long story short, it will be bad. It will be precisely what Morrison doesn’t need, at the worst possible time.

If Phelps wins on Saturday night, it will be the sum of its parts, it will be what happens when a government becomes strangely entranced with perpetrating recurrent acts of self-harm, but it will also point to a dynamic in Australian politics that is transformative in every respect.

Given Australia’s major parties over the past 10 years have taken their own #stability premium, and trashed it, they have invited voters to imagine a model of political representation that is more local, less tribal and more community focused.

They have invited Australian voters to experiment with something new. Once independents get established in federal seats, recent experience shows they are very hard to dislodge, because voters like what they see.

The times are changing in this country, election contest by election contest, and the irony is the major parties, once the ramparts of the Australian public square, seemingly impregnable, have been the primary enablers of their own disruption.