Muller’s resignation as leader of the party is a shock; nothing like this has happened in recent New Zealand political history.
But it has been clear for a week that all was not well within the National Leader’s office.
Things appear to have reached a peak over the weekend with suggestions that crucial staff were considering resignation.
Even campaign chair, the normally unflappable Gerry Brownlee, was said to be considering his own position.
Instead, he found himself in Auckland, talking to Muller about the crisis.
There was evidence that things were deeply wrong when deputy leader, Nikki Kaye, appeared on “Q+A” on Saturday.
Given the issues National faced, it would have been expected that Muller himself would front, but he apparently decreed that no-one should appear.
Kaye obviously decided the Covid-19 leaks were too serious to go unresponded to.
It seems Muller had become increasingly dependent on Kaye.
In some ways, she seemed to have a higher profile than him.
But she came with problems. She is a polarising figure within the caucus, many of whom feel she is too urban and too liberal.
Some have also questioned her political judgement.
It is believed her friendship with Michelle Boag was behind his reluctance to condemn Hamish Walker last Tuesday night over the leak of the Covid-19 names.
There was another sign, when, over the weekend of May 26, Kaye and the third member of what caucus members had come to call “The Triangle” of leadership, Amy Adams stayed in Wellington to work on the front bench lineup while Muller went home to Tauranga.
Usually, the leader would do that job.
There was concern within both the party and the caucus that Muller did not seem to have a plan for how to run his leadership.
However, when Gerry Brownlee took over as campaign chair, there was some relief in the caucus with the belief that an experienced pair of hands was in the inner circle.
But within the caucus, there appears to have been confusion.
Significant Government policies — like last week’s three waters announcement — were announced with no reaction from National.
Finance spokesman Paul Goldsmith’s response to the smelter closedown was simply to say he hadn’t been briefed.
POLITIK understands National’s Invercargill candidate, Penny Simmonds, had become so frustrated with the non-response from Wellington that she took her concerns to the party’s Botany candidate and possible future leadership contender, Christopher Luxon.
On the surface though, things looked under control.
Even the party’s internal polling apparently suggested that ironically with NZ First below five per cent and the Greens struggling it pointed to a possible National Government after the election.
That was how close Muller might have come to being Prime Minister.