On tomorrow's Tauranga byelection, Prime Minister Jacinda Ardern's future may depend.
Five years ago, a popular Prime Minister turned up at his party's headquarters in Mt Roskill to learn that its candidate had won just 27 per cent of the vote, compared with the 42 per cent party vote it secured in the general election two years earlier.
Neither John Key nor his National Party had any expectation of winning Mt Roskill, held easily by Labour with one exception since 1957, when National's Gilbert Myles nudged out Labour's Phil Goff by just 644 votes in 1990.
Nevertheless, the shocking swing against the governing party cemented Key's decision that Bill English would be a better bet for National in the 2017 general election.
There is no possibility of Labour winning Tauranga tomorrow. Yet the byelection will be the first indication of whether the polls suggesting Labour is on its way out next year accurately reflect sentiment on the ground.
In 2020, Labour and the Greens won a combined 20,954 party votes in Tauranga, 47 per cent of the total.
Add in New Zealand First, and the three incumbents won 51 per cent of the vote.
Despite Tauranga's current reputation as a National fortress, it wasn't that far off the 60 per cent the three won across the country.
The Prime Minister, Labour and the Greens could therefore be in for a pleasant surprise.
According to the latest poll, by Kantar for TVNZ's Q+A, Labour's Jan Tinetti — in practice also representing the Greens, who aren't standing a candidate — is on 35 per cent.
Given the cost of living crisis, the fall in house prices, the rise in interest rates and New Zealand being halfway to recession, Labour and the Greens would be quite happy with 35 per cent.
In fact, Labour will be hoping for a little more.
The poll was taken before the Prime Minister launched her crackdown on law and order on Monday, replacing the more liberal Poto Williams as Police Minister with Chris Hipkins, who is seen as being more from Labour's right.
Despite what we now know was a circus at the Ministry of Health, Hipkins made the Government's Covid-19 response look at least moderately competent since he took over from David Clark in November 2020.
Hailing from the semi-provincial and fairly conservative seat of Remutaka, Hipkins shouldn't have too much difficulty getting the much more capable senior leadership team at Police to refocus on threshold competencies and rebuild public trust.
The Kantar poll was also taken before Ardern expressed such confidence in rising star Tinetti by promoting her to be de facto minister for the nation's schools.
Having been principal of a high-performing Tauranga primary school as well as a regional teacher union boss, Tinetti is popular and clearly committed to the electorate, with creditable showings when she stood for Labour in both 2017 and 2020.
If anyone can make Ardern wish she had made the trip to Tauranga for Labour's election-night party on Saturday, it is Tinetti.
Conversely, if Tinetti's vote falls below 30 per cent, despite there being no Green, NZ First or Te Pāti Māori candidate, Ardern will have been right to remain scarce.
A 20-plus swing against the left since 2020 would confirm Ardern's unre-electability, as suggested by recent polls.
If Tinetti is a local Labour candidate from central casting, National's Sam Uffindell has been flown in as a cardboard cut-out from the party's Key-English-Joyce era — although lacking in their charisma. After its more disastrous candidate selections in recent years, National chose to play it safe.
Despite his unprecedented national unpopularity that saw a majority of National MPs vote to oust him as leader in May 2020, Simon Bridges won 18,721 personal votes in Tauranga in 2020, 43 per cent of the total, and a better-than-average 14,437 for his party.
Byelection turnouts can be much lower than in general elections. In Mt Roskill in 2016, just half the usual number turned out.
In Northcote in 2018, it was 56 per cent.
The big recent exception was in 2015, when Winston Peters managed to get 83 per cent of the usual number of Northlanders to turn out and elect him MP, an early expression of the provincial anger behind Groundswell and the anti-vaccine movement.
Anger against incumbent Governments fuelled turnouts of nearly 100 per cent of usual numbers in Selwyn and Timaru in 1994 and 1985, and nearly 85 per cent in Tāmaki in 1992. In Taranaki-King Country, two-thirds showed up in 1998 to put the boot into Jenny Shipley's Government after she rolled Jim Bolger.
If there really is a big swing against Ardern and towards Christopher Luxon, National will be wanting at least 30,000 voters to show up before polls close tomorrow, and at least half of them to tick Uffindell.
That would suggest Luxon had at least managed to inspire all the National Party voters who reluctantly backed Judith Collins in 2020 to show up again to oppose Ardern and endorse his new direction.
The key indicator will be whether National and Act together match the 18,000 or so votes they won the night of Collins' nadir.
To prove there's a roll on for Luxon, they'll want their combined vote to at least match the 57 per cent they won in 2008.
Given NZ First managed over 10 per cent that year despite the Spencer Trust scandal, National and Act won't really deserve to crack open the champagne unless their combined vote has a six at the front of it.
In particular, they won't want fringe right-wing candidates like Sue Grey, Andrew Hollis and Helen Houghton — of the Outdoors, New Nation and New Conservative parties respectively — to get into even triple figures.
Of the centre-right vote, Act will need to come close to the nearly 9 per cent it won in 2020 with the same candidate, local party stalwart Cameron Luxton.
Tauranga has never been kind to Act, but anything below the 5 per cent it averaged in Tauranga in the decade after its founding would be disastrous, suggesting it will be unable to cut itself free of National's Epsom umbilical cord in 2023.
If Act can't get back to Parliament next year on its own merits, then it will have no chance of having leverage over a Luxon Government. There is every incentive for the 1739 Act voters who backed Luxton in 2020 to do the same tomorrow, or David Seymour and his crew may as well just give up.
Most likely, no one will be very happy tomorrow evening. Except maybe the Greens and NZ First, who perhaps wisely decided not to put themselves to the test in Tauranga's sometimes fickle electorate.
- Matthew Hooton is an Auckland-based public relations consultant.