WHEN it comes to political legacy, the end of a premiership is as important as the tenure.

How depressingly refreshing then to see a prime minister leave on their own cognisance, scandal-free and for the right reasons. Depressingly, of course, because it's so sorely lacking in global politics.

Jacinda Ardern, New Zealand's postgirl for a new kind of politics, has stepped down in a resignation that shocked both Kiwi voters and a global audience taken with her particular brand of stardust. It also leaves her party in a sticky position: nine months out from a general election with an opposition rising in popularity and no clear new leader.

Still, Ardern has had a nightmare shift, dealing with multiple crises. Yet the suddenness of her going comes as less of a surprise when you consider what sort of leader she was.

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Her premiership was not without its difficulties and, while overseas she is seen as a shining beacon of progressiveness, her party's record is mixed. There were accusations that Labour failed to get down into the nitty gritty of policy pledges, such as a promised housebuilding scheme that has not been delivered, and a lack of legislative reforms.

Carbon emission targets have not been met and fiscal conservatism prevented progressive tax changes that might have funded social programmes. As she steps down, New Zealand is experiencing inflation and high interest rates that her incumbent will have the unenviable task of tackling.

But, despite criticisms, she remains ahead in the polls as the most popular prime ministerial choice and was instrumental at the last election in bringing swing voters across to Labour from the rival centre-right National party and was expected to do so again.

In her six years in office, Ardern determined to do things differently. When New Zealand went into lockdown at the start of the coronavirus pandemic, Ardern asked her fellow Kiwis for strength and kindness.

Those tenets have been her constants. From being the country's youngest-ever PM to being only the second premier to have a baby while in elected office, Ardern has shown an emotional intelligence that propelled her to global fame far beyond New Zealand's usual political clout.

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She was exceptionally adept in dealing with crises and had a skilful ability to understand what people need in the face of devastation.

But actions designed to comfort in the immediate aftermath of calamity were then followed by meaningful action. She appeared wearing a hijab to meet with Muslim communities in a mosque following New Zealand's most serious terror attack in Christchurch but then launched a demand for bipartisan gun control legislation just days later.

A face of compassion but a backbone of steel, Ardern used this template to deal with further crises during her tenure, not least the uncompromising response to the coronavirus pandemic.

Her force of personality and her popularity - Jacindamania - saw Labour grasp victory in 2017 from what had been almost certain to be a defeat. The then-prime minister Bill English famously referenced her "stardust" – a comment meant as a criticism but an epithet that stuck and became a compliment.

But her zero-covid approach has, in recent months, become a target for conspiracy theorists and the country's approach to Covid-19 vaccinations has made Ardern the villain of anti-vaxxers.

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New Zealand has seen unprecedented protests and violence from these groups outside the Beehive, the parliament building, while Ardern, during her premiership, was the target of constant sexist and misogynistic abuse.

Often throughout the pandemic Ardern's empathy, morality and decisiveness was held up as a mirror to our own leaders' corrupt incompetence. Her decision to step down, rather than cling on for the sake of it, shows a dignity often lacking in politics.

To know when to go is a powerful thing.

The October election is set to be bracing for whoever succeeds Ardern with National party gaining ground in the polls. In 2020, at the last general election, she achieved a majority win - rare under New Zealand's mixed-member proportional (MMP).

Her sudden departure shows just how personality politics are a gamble for a party. They wreak intense havoc when the personality who woos an electorate is disreputable, power hungry for power's sake and interested only in self-service.

It's a gamble still when the party ends up with a star like Ardern because, despite being the flip side to the likes of Donald Trump or Boris Johnson, you risk them walking away and leaving a potentially unfillable gap.

Ardern also leaves a gap on the world stage. She personified the maxim about women rejecting the temptation to adopt typically masculine traits in order to get ahead in a man's world.

A media outlet asked earlier on Thursday if Ardern, after resigning saying she wants to spend more time with her daughter and marry her long term partner, demonstrates that women can't have it all. The post was removed following a flame of outrage at the question.

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It's not a sign of failure or weakness to quit while you're ahead. Ardern cites burnout as the reason she doesn't want to push on and that will resonate with a great many women burdened by the constant juggle of work and family, those who would like to say no or step back but who can't.

Ardern disputed in her leaving speech that she had run out of political gas. Instead, she claims a lack of personal gas. "I can tell you that what I’m sharing today is the only interesting angle that you will find," she said. "That after going on six years of some big challenges, I am human... and I know that I no longer have enough in the tank to do it justice. It’s that simple."

For others in politics, this statement would not wash. The hunt for scandal would be on. With Ardern it seems not just plausible but logical that she would be motivated to do the right thing, to put everyone else first – daughter, partner, the country – by putting her wellbeing first.

As a politician who set out a national budget based on prioritising wellbeing, she is only practising what she preached. That's the lesson of Ardern's leadership and one others could do very well to heed.