Yes, there is the "Winston factor". More on that later.
But the reality is that neither Ardern nor Finance Minister Grant Robertson has made a concerted effort to go over the head of Labour's coalition partner and make a case to the public to support the introduction of a broad capital gains tax regime.
The blueprint presented by the Tax Working Group led by Sir Michael Cullen might ultimately have proved unfeasible. But if there had been some modifications, such as reducing the top rate at which the capital gains taxes applied, it should have got over the line and achieved public support.
The problem is that 33 per cent is at the upper end of OECD capital tax rates, level-pegging with Finland and Ireland. Just Denmark at 42 per cent and France on 34.4 per cent are higher.
Some other countries pitch them lower: Mexico, for instance, at 10 per cent and Greece at 15 per cent.
But even the home of capitalism — the United States — has capital gains taxes and distinguishes between short-term rates and long-term rates.
Ardern claimed that it was "time to accept that not only has a Government that reflects the majority of New Zealanders not been able to find support for this proposal, feedback suggests there is also a lack of mandate among New Zealanders for such a tax also."
She added that in short, "we have tried to build a mandate, but ultimately been unsuccessful." This is disingenuous.
Capital gains tax regimes have been at the heart of Labour's policy thinking for at least a decade now. Ardern could have built a mandate from among her own party's supporters.
But the only mandate that she appears to have sought was that of New Zealand First.
In fact, there were options. The capital gains tax could have been set at a significantly lower rate than the top personal income tax rate, and carveouts made for businesses and farms under a certain threshold as had been advocated in prior Labour policy. The bright line test could also have been extended for investment properties.
This would have demonstrated a commitment to at least moving towards establishing equity in New Zealand's tax system.
Instead, Ardern has made yet another of her captain's calls on tax.
It is worth remembering that former Labour leader Andrew Little took Labour's capital gains tax policies off the table when he became leader.
In her first flush as Labour leader during the 2017 election campaign, Ardern put them back again, saying it was a captain's call. But ultimately she took capital gains tax off the table again after Labour lost support in the polls.
She promised not to introduce such a tax in Labour's first term in Government. Instead, a working group would be tasked with framing options; the Government would introduce empowering legislation. The capital gains taxes would not, however, take effect until 2021.
The upshot is that Labour would have sought its public mandate at next year's election.
It is simplistic to blame New Zealand First for this defeat.
New Zealand First did not rule out a capital gains tax within the Coalition Agreement.
But neither did Labour specifically require New Zealand First to commit to empowering legislation by making it a confidence matter.
The lesson from this is that major parties which get into bed with more muscular junior parties to form Coalition Governments better make sure their own signature policies will be supported.
Yesterday, American magazine Fortune named Ardern as the world's second greatest leader for her leadership after the Christchurch mosque attacks. "Jacinda Ardern had already broken new ground as a pregnant woman — and then a new mother — leading a nation," they wrote in their list of the Top 50 World's Greatest Leaders.
"And this year, the 38-year-old Prime Minister showed the world her fullness as a leader as she deftly, empathetically, and humbly navigated New Zealand through the worst terror attack in its history, after 50 were killed at two mosques in Christchurch in March."
Fortune praised her rallying skills. Ardern has those in abundance. Pity they were not used this week.
