OPINION: Peter Dunne was supposedly the great survivor who nothing could take down - then along came a flying Jacinda Ardern and surging Winston Peters.
In terms of the Ardern effect, polling has shown Labour's grown in popularity in Ōhāriu, which should be a safe centre right seat - so Dunne quit rather than lose to Labour.
But Winston Peters also gave him a push out the door. His role as kingmaker is so cemented, he'd made Dunne irrelevant.
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Sixty-one seats are needed in in the House for a majority. Looking at the latest Newshub-Reid Research poll, National had 55, then with the Māori Party, Act and Dunne, a total of 59.
But Winston Peters' New Zealand First had 11 seats - National would need Peters to govern.
He hates Peter Dunne and would rule him out of any role, putting him into Opposition.
So even on a best case scenario of getting back into Parliament, Dunne would have been powerless.
No matter what happened, he was going to lose. So he walked instead.
Now the big worry for Bill English is that Ōhāriu is what's called a "bellwether" seat, where the shift from the centre right to Labour in one electorate reflects a wider change around the country.
Peter Dunne was unable to contain the pain at quitting, breaking into tears.
"I am a mix of emotions. I'm relieved that today has come. I'm a little sad and a little confused because this has been half my life in this place - it was a big call."
The worm has finally turned and the 'Ardern effect' has Peter Dunne sensing change.
"I think what that's done is open the possibility of change," Dunne said today.
National had done what's called a "dirty deal", where it encouraged its supporters to vote for him.
It was so blatant its candidate, Brett Hudson, had written to voters saying: "In Ōhāriu, we're asking that you tick National and tick Peter Dunne."
Now Bill English is telling voters to do something completely different - to vote for Hudson.
Peter Dunne's political marathon had plenty of highlights, like the 'worm' in 2002 televised debate.
The lowlight was quitting as a Minister after being accused of leaking a spy report.
His political legacy: being known as "Mr Common Sense".
In the end, political common sense prevailed - he's chosen to quit rather than lose.
Patrick Gower is Newshub's political editor.