It was a matter of stability and trust on the red side vs a shambles and negativity from the blue side - and electoral carnage not predicted.
Judith Collins' best was not good enough and she has been utterly rejected by the electorate.
The election is a vote of confidence for Ardern's style of leadership in which she does not bow to the accepted convention of popular leaders needing to sound tough.
She is a celebrity Prime Minister and is comfortable being so. The shopping mall mobs encountered over the campaign could have been avoided or reduced if she were uncomfortable or did not want to reinforce her celebrity status.
But there is much more to her leadership than that and people would not have put their trust in her without more.
Ardern clearly has steel in her backbone when it is needed. You just don't get to have led the country through what she has without it.
The result is also a vote of confidence in Labour's Gang of Four - as well as Ardern, Finance Minister Grant Robertson, Health Minister Chris Hipkins and Ms Fix-It and campaign manager Megan Woods.
They have not only led New Zealand through the twists and turns of Covid, they have effectively controlled the Labour strategy of replacing an election campaign with "governing to the end" and taking a minimalist approach to political promises.
The less the Government looked the Labour Party during the campaign, the more likely the soft National supporters would stay with them.
It was Covid-related Government decisions, not Labour promises, that were being wheeled out the last week of the campaign - on international students and deals for vaccines.
There were two other reasons for under-promising by Labour in the campaign: first it knew that the promise of Ardern's leadership was worth more than any other usual hustings offerings and second because so much about the immediate future is still uncertain.
As Robertson often says, he does not know if we are in the middle of an economic crisis, or at the beginning or perhaps at the end of the beginning.
The decision to under-promise is not without its challenges especially for a Labour Government, whose activists live and die for policy.
The mandate Labour has received at this election cannot be a mandate to do nothing. But nor can Labour exceed its mandate by imposing big policies it has not consulted the electorate about.
The party leadership needs to spend some time working out the Labour it wants to be or if it is going to spend the rest of the term trying to keep the centrists with them.
This is a huge night for Labour. In the nine elections under MMP, the party has been able to truly celebrate the result the night only three times.