OPINION: There is this thing John Key does after the daily media scrum on his way into question time that is quite revealing. Once everyone's done, he hunches his shoulders to make himself smaller so he can scoot through rather than barge past, despite the entourage of police and media minders who are probably itching to do so on his behalf.

It's a habit that hasn't changed in seven years, much like Key himself. Maybe that explains Key's enduring popularity. People quite liked Key when he became National leader all those years ago and they still quite like him now though he has become more polarising. It's one reason why – two terms later and midway through his third – talk about Key winning a fourth term no longer seems preposterous. If anything, the opposite is true.

So what's Key's secret? It's a question asked not just by the succession of Labour leaders who've come to understand the true meaning of futility after throwing themselves against the impenetrable Key fortress for years.

Column inches have been written in newspapers and magazines around the world exploring the reasons for the Key government's success. There are also plenty of questions about it from curious foreign leaders whenever Key attends an international gathering. And no wonder. Key has seen off so many other world leaders, he is now one of the older hands at all those international gigs.

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* A tale of John and two Malcolms

* Key and Turnbull – a trans-Tasman dream team?



There is no real mystery about much of Key's popularity – he's likeable and even his gaffes make him seem more approachable (National's support went up after the infamous "soap" gag that sparked howls of outrage about its rape allusions, for instance), and when he makes a call like abandoning Waitangi, he is unfailingly in tune with public sentiment (helped along by National's nightly polling, no doubt).

But his style of government is often also cited. When Australian Prime Minister Malcolm Turnbull rolled Tony Abbott, he banked a huge amount of early political capital, in part by blatantly stealing from the Key playbook, by promising to run a more consensual government. He even spelt out that plan in his first speech as leader: "My firm belief is that to be a successful leader in 2015, perhaps at any time, you have to be able to bring people with you by respecting their intelligence in the manner you explain things ... John Key for example, has been able to achieve very significant economic reforms in New Zealand by doing just that," Turnbull told Australians.

As a mark of his admiration, Turnbull even reversed the normal order of things in trans-Tasman relations by flying across the ditch to meet Key as one of his first international engagements, rather than expecting Key to make the first move.

But it might be that Key just makes it look easy.

Because as Turnbull is discovering the Key handbook will only get you so far.

The Turnbull administration is in disarray as he loses a succession of ministers and deals with leaks from his enemies within the caucus. So wide are the splits and divisions in the Liberal Party that Turnbull has already been forced to abandon one of the first major policies of his prime ministership – ironically one he semi-filched from Key, raising GST.

What Turnbull may have missed in the fine print is that even Key doesn't always follow "the rules". The GST hike was one such example – there wasn't much of an effort to soften people up for its introduction, Key's assumption being that he had enough capital in the bank to get it through without without too much collateral damage.

So Key's advice to Turnbull would have been that there are times when its worth waiting to take people along with you, but there are also times to move quickly and decisively. In Turnbull's shoes, he would have reshuffled his Cabinet without delay, and used the public support that swung behind him to move just as swiftly in implementing a few key measures.

And that's the other piece of advice Key would probably give Turnbull. The public really don't sweat the small stuff in the same way that us Wellington insiders do. As long as they think the Government is moving in the right direction and they respect their overall management of the big stuff – the economy, health and education, roads and all the other things that touch on their daily lives – they'll have faith that the Government is getting the other stuff right.

There are other factors at play as well of course – a souring economy will quickly stoke a mood for change. But international volatility aside, the election looks likely to be held against the backdrop of a largely benign economy, with things like low petrol prices, record low interest rates and an ongoing construction boom ($6 billion in the Auckland CBD alone over the next few years) likely contributing to a general mood of well-being, though the rural sector will still be hurting.

If the wheels start to fall off any of those things, that may be the day the wheels also start to fall off National. Because if there's one downside of being such a popular government for so long, it's that National's bulging back benches are filled with MPs who have no understanding of what it's like to be A) unpopular and B) facing the prospect of defeat.

Even Key barely knows that feeling. Only a few veterans like Bill English, Nick Smith and Murray McCully remain from those years when the electorate was well and truly out of love with National and that experience helped shaped the Government we see today. And as they would know, the real giant killer in politics is disunity.

That was clearly a lesson well learned, given that it is the area where National has been most disciplined for the last seven years.

But as history keeps reminding us, unity that takes years to build can easily be undone.