But Luxon has clawed National back from being 13 points behind Labour to being two points ahead of them. Back in November, just before Luxon took over, National was on 28 and Labour on 41 in the 1News poll. National is now on 39 and Labour on 37.
That is a massive shift in just four months. And once a new leader gets momentum, it tends to snowball as Ardern herself knows. People like to back a winner.
Luxon was at 25 per cent and Ardern holding steady at 34 per cent as preferred Prime Minister – but Luxon was up eight points, a sign people were now making up their minds about him and were not displeased.
The result was a lot closer in a separate poll question which asked people to choose between either Luxon or Ardern as their preference for PM.
In that Luxon was on 45 per cent and Ardern 46.
The breakdown of how people voted in that question contained a number that should worry Labour: Luxon had won Auckland. Fifty-one per cent of those in the key battleground of the biggest city had chosen Luxon.
The other worrying thing for Labour is that while Luxon's early ground came from taking votes back from Act, National is now eating into Labour's support as well. The National-Act grouping were a smidgen ahead of the Labour-Green grouping.
And the biggest element in the Government's torrid few months will not go away any time soon: the rising cost of living. Pessimism about the economy had risen to 53 per cent while optimism was at 28 per cent.
Since coming back from the Christmas break, Luxon has focused solely on the economy and the cost of living when going up against Ardern in the house.
He also focused on it in his state of the nation, after earlier intending to focus on education. It has paid off for him. Luxon is due to give his MPs their performance reviews in the next week or so. He can probably give himself a pass mark.
His key job was to put National up as a credible alternative and to take back the high ground when it came to economic management. Luxon has done just that.
The polling will also help him in keeping the rest of his MPs in line: good polling and the sniff of a chance at getting back the ministerial benches tends to be a cure-all for ill-discipline.
The job isn't done yet. On Thursday's poll, the balance of power was held by Te Pāti Māori. If that is the case on election day in 2023, it would likely see National dispatched back to Opposition.
But the next election will be a humdinger. If Labour does not have a few tricks up its sleeve, it needs to start shopping.