This week saw National Party leader Christopher Luxon reach for the "PM must resign" card for the first time since he took over – a card that should be used sparingly, if at all, by Opposition leaders.
It appeared to be an on-the-hoof call, rather than pre-determined.
He wasbeing pushed on whether he believed the Government would stick to the opening dates it had set out for the border re-opening.
He said Prime Minister Jacinda Ardern should resign if she changed the dates again.
He probably rued saying it the minute it came out of his mouth.
If calls to resign are over-used, they lose impact. They also look like desperation.
Nor would this be something to resign over. It is clear it would take something very big indeed for Ardern to once again delay that re-opening for New Zealanders to come in.
If that big thing did come along – a new, super-vicious variant – then Ardern would stand accused of neglect if she did not act.
Instead, Ardern's announcement on the border re-opening saw her take lean on the John Key playbook that was once dismissed as reckless.
She did what Key proposed during the Delta lockdowns: set a firm date for the borders to open and tell people it was up to them to get vaccinated before then.
On Thursday, Ardern said by the time Kiwis can come back without MIQ, more than 90 per cent of those vaccinated would have had a good chance to get their booster. It was up to them to get it by then: the dates were firm.
If she had followed her Delta playbook, she would have set a boosters target before moving on the borders. Admittedly when Delta arrived, most New Zealanders were totally unvaccinated. This time round it is less perilous - but the boosters are best for Omicron.
The reason she did that was because of the growing anger at MIQ, the lower danger of Omicron, and the growing belief of many in Cabinet that the time had come to get on with re-opening - no matter what.
It is very rare that a single thing can bring down a government, even if it is a big thing.
More often, it is the accumulation of small, corrosive barnacles slowly attaching themselves to the hull and weighing it down until eventually the weight gets too much and it sinks.
Ardern is finding just that when it comes to Covid-19. Ardern is not the only political leader in the world suffering in the polls at this point of proceedings. The initial poll boost other leaders got in the first year of the pandemic for crisis management has worn off. People who once blamed the virus are now blaming politicians. Ardern is probably the best-placed of them.
But there are barnacles. Ardern is now trying to address those barnacles without adding another one, in the form an out-of-control Omicron outbreak.
Delta was the biggest barnacle, the lockdowns of last year were responsible for a big hit to the PM's popularity. The initial slow pace of the vaccines rollout was another, and was the reason the lockdowns were needed to start with.
The Prime Minister would undoubtedly like history to record that New Zealand was one of the most highly vaccinated countries in the world by the end of 2021, without mention of the first eight months of that year.
MIQ turned from a saviour to a major barnacle in the end. Smaller barnacles popped up over issues such as the failure to get early and large supplies of things such as vaccines and, recently, rapid antigen tests.
It takes a lot of grit for a politician to hold the course on unpopular actions, knowing it will hit you in the polls. And it has hit Ardern in the polls.
Ardern herself has acknowledged that, but also claims she refused to let the pandemic be governed by polling.
Despite that, we are at the point where more decisions could be made for political rather than health reasons. Until recently, the health factors and the political factors have coincided. The best health response was the best political response.
The overall feeling people had of safety was better for the Government politically than removing some of the restrictions because they were becoming unnecessary or ineffective.
Things are more in the balance now, however.
There is a division of opinion on the wisdom of the border opening during an outbreak, and on whether red is enough for the Omicron outbreak.
At the start of her speech on Thursday, she said she hoped the border announcement would be the starting point of a time when people once again talked about the weather instead of Covid-19.
What Ardern needs is for people to change the habit of the past two years – and stop being terrified of the virus without getting too slack about it.
However, New Zealanders have had two long years of believing travellers will bring the evil Covid in. That has not changed – many will be worried.
But it is no longer as relevant: Omicron is already in the community, and the country is among the most vaccinated in the world. We are, as the PM says, in a much better position than others have been.
Our hospital system is the reason for slowing the spread: we have less ICU capacity than many other countries which have been overwhelmed by Omicron, despite its lower severity.
But what use it will be no small challenge to change the now-entrenched mindset of many of the New Zealand public. Even now, with very high levels of vaccinations, a sizable clump of people think MIQ should stay in place and stricter measures taken to thwart Omicron.
The economy is another reason the Government might hope people become less fearful.
Finance Minister Grant Robertson said on Thursday the challenge under the red setting was human behaviour rather than the rules: just because businesses could open did not mean people would go to them.
Many people are treating the red setting as a self-imposed quasi-lockdown – both to avoid getting sick and to avoid having to isolate for a prolonged period.
In an interview with the Herald, Ardern clearly believed that would pass as time went on and people simply got sick of it.
She noted in other countries once people got used to living with Covid and they did so fairly happily – they simply got on with it. That shift has simply come later to New Zealand.
The people in those countries are now looking with incredulity at New Zealand, wondering why it is so worried about Omicron.
Ardern has also learned that backtracking on promises hits the trust in her. Luxon's resign comment was prompted by trepidation among those overseas about whether the Government would stick to the dates this time.
Charlotte Bellis, whose case sparked the furore over MIQ last week, was among those. Bellis secured a spot in MIQ – and if all goes to plan, she will be one of the last New Zealanders to have to go through it.
On the day Bellis was offered and accepted a slot in early March, Cabinet signed off on the dates for ending MIQ. That included the March 13 date which would otherwise have applied to Bellis. That is around the date she would be emerging from MIQ.
She told the Herald she was now weighing up whether to wait until she could home isolate on March 13 and risk the dates changing or stick to the MIQ slot, given it was a certainty.
That timing almost feels like a last laugh by MIQ – or Cabinet.