With National's most highly regarded provincial conservative and most popular urban liberal having been sacked or quit, Bridges would have even less chance of turning things around than before this week's first terrible poll.
Realistically, the purge would have to go much further. It would need to catch the likes of foreign affairs spokesman and party doyen Gerry Brownlee, who flatted with Muller in the 1990s, and party star Chris Bishop, who took Hutt South off Labour in 2017 for the first time in the working-class seat's existence and has led the numbers operation for Muller.
Corrections spokesman David Bennett would also be for the chop, after revealing to constituents he was involved in the plot.
In fact, any true purge may need to include even deputy leader Paula Bennett and defence spokesman Mark Mitchell who, some MPs claim, have been promoting a plan where they would take over from Bridges if National's polling did not improve by this time next month.
It makes me sad that things have reached this point. Bridges and Kaye have been personal friends of mine for 13 years, and Muller for more than 30.
Bridges' fall is directly related to his unfortunate lack of political judgment. In the early days of his leadership, he mortified colleagues by making jokes about the gender of the Prime Minister's daughter, for which he stubbornly refused to apologise.
Worse, he no longer seems to learn. Even this week, Newshub trapped him into a similar faux pas over the Prime Minister dyeing her hair.
Labour strategists have been drooling in anticipation of regular gaffes on the election trail.
Bridges' decision to go public on Wednesday morning about the growing probability of a leadership challenge was a more fatal miscalculation. His blurting out the existence of a plot ended up solidifying Muller's support.
Even then, it might not have been so bad for Bridges had Muller and Kaye's names not been immediately leaked to the media, for which Bridges' office is widely blamed.
The die was then cast and Muller and his preferred deputy Kaye disappeared from view. By mid-afternoon, Muller had made the final decision with his wife and three children to proceed, formally requested chief whip Barbara Kuriger hold a leadership vote as soon as convenient, notified party president Peter Goodfellow of what was happening and prepared an email to his colleagues.
Bridges did not take Muller's call before the email was sent, instead bringing forward the vote to today in any effort to deny the challenger momentum. That, too, may have been a miscalculation, prompting headlines about an emergency within the party.
This lack of judgment was most exposed during the Covid-19 crisis. Many of the points Bridges made critiquing the Government's performance at least in the early stages were fair enough. But, increasingly, the position he would take one day would contradict that taken the day before. It was quite clearly opposition for opposition's sake.
Consequently, Bridges' leadership has been unsalvageable for some time.
It is true that National and Labour-Green were too close to call in the October, November and February Colmar-Brunton polls, but they were tiny specks of blue in a nearly three-year sea of red. Moreover, they are polls from another era.
National is now further behind Labour than it was even on the night of the 2002 election catastrophe. At least 16 seats in Parliament would be lost, including those of some of the party's most important rising stars.
National's optimists say the gap is bound to narrow as the election nears, the depression bites and unemployment soars.
But no less than in equity or currency markets, past performance is no indicator of future results, one way or the other. There is no guaranteed rule of reversion to the mean.
As in 2002, once National is quite obviously facing a debacle, it risks a further flight of its supporters to smaller parties. Liberals who want to give it a kick risk ticking Act. Grumpy conservatives might flow to the New Conservatives. National supporters who want to place a brake on the Labour-Green alliance would quite rationally vote for NZ First. Some may even go to TOP.
It does not take large numbers of each to drive National down to the low 20s. Losing 16 seats on election night risks being just the start.
Muller, of course, might completely fail, in which case the leadership would pass before the end of September to either the ever-patient Judith Collins or the incoming evangelical Christopher Luxon.
But Muller has been a senior executive at Zespri, Apata and Fonterra. After 20 years in business, Muller gave up an $800,000-a-year salary to fulfil his boyhood dream of representing his local community in Parliament. He can read a balance sheet and profit and loss account as well as anyone — and, more importantly, know whether they look good or bad.
He can make a pitch that he and National's indispensable finance spokesman Paul Goldsmith are better than Ardern and Grant Robertson to manage the expenditure of the $140 billion that last week's Budget suggests New Zealand is set to borrow.
It may not be the most brilliant or visionary pitch, but it might contrast well with a Labour front bench made up of former student presidents and prime ministerial staffers — of which, ironically, Muller is also both.
It is certainly better than National limping to certain catastrophe under a leadership that, sadly, has so obviously failed.
Matthew Hooton is an Auckland-based PR consultant and lobbyist. As noted in this column, he has been a personal friend of Todd Muller for 30 years and has spoken to him during recent events. These views are his own.