Whatever happened to Jacinda Ardern? It’s a reasonable question to ask about the former New Zealand Labour prime minister as that nation heads to a general election on October 14 – the same day as Australia’s constitutional referendum on the voice.

As the saying goes, it’s unwise to make predictions, especially about the future. Less than two years ago, it was expected by many that Ardern would be a long-term prime minister. She became Labour leader seven weeks before the October 2017 election in which the party narrowly defeated the politically conservative National Party government led by Bill English.

Three years later, Ardern led Labour to its greatest victory since New Zealand introduced its mixed-member proportional representation electoral system (MMP). Ardern’s party won 50 per cent of the primary vote and was able to form a majority government – a rare feat under MMP.

In October 2020, Ardern and Labour seemed unassailable. Now, three years later, Labour is trailing the National Party in the polls and is the underdog going into next Saturday’s election. Certainly, there appears no hope Labour could win government again without the support of such left-wing entities as the Green Party and the Maori Party. In other words, it’s a minority administration at best.

At the beginning of 2021, Ardern was widely regarded as the star of the Western democracies. She was lauded in the US media. There was a similar cult following in Australia.

In December 2020, Black Inc’s Quarterly Essay published a long article by ABC journalist and Australian Financial Review columnist Laura Tingle. It was an occasion where a book can be judged by the cover. Titled “The High Road: What Australia Can Learn From New Zealand”, the essay praised what was later termed Ardernism. But by January 2023, Ardern had gone and Ardernism, to put the saying in its proper chronological order, was dead, cremated and buried.

What happened? In early January 2023, the Taxpayers’ Union-Curia Poll showed the Labour primary vote was down to 31.7 per cent and Ardern was viewed less favourably (41 per cent) than favourably (40 per cent). A reasonable approval rating to be sure. But a dramatic decline in support for someone who had been the most popular leader in contemporary New Zealand politics.

Ardern’s popularity reached its zenith during the Covid-19 lockdowns – probably as harsh in New Zealand as they were in Victoria. It would seem, however, that Australia’s neighbours “across the ditch” became more disillusioned with the harsh restrictions than their counterparts in Victoria and some other Australian states.

But there was more than that. Ardern made the fatal flaw of over-promising and under-delivering. As Matthew Birchall pointed out in these pages in January, Labour swept to office in late 2017 with a proposal to solve New Zealand’s housing crisis.

Ardernism included a you-beaut plan with the cute title of KiwiBuild to construct or deliver 100,000 homes by 2028. However, by May 2022 only 1300 KiwiBuild homes had been delivered.

There is a lesson here for the Victorian Labor government. Shortly before he retired from politics a few weeks ago, Labor premier Daniel Andrews released Victoria’s Housing Statement. He wrote that “we’re setting a bold target to build 800,000 homes in Victoria over the next decade”. Bold indeed. 800,000 new homes in 10 years when New Zealand could only manage 1300 in just over four years. Do the math – as Americans would say.

Currently, Ardern is at Harvard University in Cambridge, Massachusetts, near Boston, having indicated she would not take any part in the election. She quit after the evident failure of KiwiBuild and continuing economic and social problems on the home front.

Andrews departed less than a year after leading Labor to a stunning victory at the state election last November. He will not be around when the success, or otherwise, of his housing plan is determined. Nor will he have to oversee the consequences of the huge state debt he bequeathed Victorian taxpayers, who will have to fund the resultant interest payments for many years.

Unlike Ardern, Andrews went out at his near top. Yet, already his record has been somewhat tarnished by Victoria’s evident economic problems. However, in view of the weak leadership of the Liberal opposition, it is far from clear that the Coalition will be in with a chance when Victoria goes to the polls in November 2026.

Meanwhile in New Zealand, the National Party, led by former businessman Christopher Luxon, is in with a chance. No one expects Luxon can achieve majority government. This has only been done twice under the MMP system: Ardern in 2020 and National Party leader James Bolger for some years in the early 1990s.

However, there is a prospect of the National Party forming a coalition government with the economic libertarian ACT party (led by David Seymour), perhaps with the assistance of Winston Peters, if his NZ First Party can win a seat. For Labour to retain government it will require a coalition with the Green and possibly the Maori parties.

If there is a change of government, the Luxon-Seymour administration will face a difficult task. Under Labour, the public service has grown while debt and inflation are high and crime is a considerable problem. New Zealand’s Labour prime minister Chris Hipkins has already shed some of the Ardern legacy with respect to climate policy and hate speech laws. But he is leading an evidently unpopular party.

Currently in Australia, media attention has focused on the precarious position of the Tasmanian Liberal Party government led by Premier Jeremy Rockliff. Many a journalist has commented that this is the remaining non-Labor government in Australia – which focuses attention on the failure of the Coalition both at the national level and in the mainland states and the territories.

However, the fate of Ardernism demonstrates there are increasingly fewer certainties in contemporary democratic politics. A couple of years ago Ardern looked invincible in Wellington. Today she is on a university campus in New York remaining silent about New Zealand and the fate of her legacy.