The closest thing the Covid response has to a rule of thumb is that politicians can never do wrong by being overly cautious.
No one really regrets cracking the whip on Covid restrictions: the likely unnecessary lockdowns of early 2021 and Wellington level 2 restrictions of June didn't shake confidence in the Government.
By contrast, National still regrets comments made by former leader Todd Muller about eventually opening the border to China. Likewise, the party copped flak for its vociferous support of the transtasman bubble, which some have blamed for the latest outbreak (likely, incorrectly - given the bubble was suspended on July 22).
It was therefore remarkable, last Friday, when National's latest leaderly incarnation so willingly waltzed into the very political graveyard in which his immediate predecessors had so recently been interred.
Luxon made the case for Auckland to be in the Green Covid setting, citing the fact the health system was coping.
So far, he has not endured the political backlash of his predecessors.
Ardern, by contrast, is beginning to wear criticism for second-guessing Covid on the conservative side. She rejected the notion that parts of the country out of Auckland could move to level 1, the suggestion Auckland could leave level 4 early, and the idea the Auckland boundary could be dropped.
Luxon benefits here from timing, something that should surprise no one - timing being essential for all airline executives.
Last year, the platitudes the Government used to defend the Covid response: "go hard, go early"; "the best economic response is a strong public health response", were very much correct.
In the absence of a vaccine, everyone was in some way vulnerable to the virus, and therefore everyone had some degree of interest in the party that could most competently manage the outbreak.
The vaccine changes this politics: people have different degrees of vulnerability based on whether or not they are vaccinated, have young children, or have sympathy with people who choose not to get the jab. It is no longer true that the best economic response is a strong public health response (although it's not clear what the best economic response looks like now).
Luxon's making the same argument National has made for nearly two years - he's simply fortunate that circumstance means the argument makes vastly more sense now than it did a year ago.
The big question here is how the change in Covid circumstances will alter its response. Two recent polls have shown significant drops in support for the Government's Covid management.
A November Talbot Mills poll showed those who rated the Government's handling as good had dropped from 60 per cent in October to just 46 per cent, while those who rated it as poor had risen from 16 per cent to 26 per cent. A Taxpayer's Union-Curia poll showed Labour's favourability on Covid drop from 57.2 per cent to 49.1 per cent (National rose from 13 to 22 per cent).
The question for Ardern is to what extent she allows her political response to be shaped by the challenge presented by Luxon.
The risk is that Ardern is framed as the backward-looking leader for the pandemic, while Luxon appears the forward-looking leader for the rebuild. The off-the-shelf political reference here is Winston Churchill who was turfed out of office months after World War II was won.
This was on display in Luxon's first Question Time as leader, in which Ardern defended her slow action on boosting ICU capacity by arguing the Government's Covid response was so successful, extra ICU beds weren't really needed - the same logic could be used to argue that good drivers needn't wear seatbelts, or that lifeboats weren't required on the allegedly unsinkable Titanic.
With National's recent weakness, the most recent phase of the Covid pandemic has seen Ardern behave like a First Past the Post leader, occupying herself with balming opposition from within her own party as much as quashing opposition from National and Act.
She fought off some not-so-subtle dissent from the Māori caucus over the traffic light system.
Should Luxon's Covid liberalism prove to be popular, she'll likely have to park the concerns on her left flank in favour of tacking to the centre.
This recalls her predecessor Helen Clark ditching the "closing the gaps" policy in response to the surging popularity of Don Brash, during the second term of her government. Oppositions are often ridiculed for morphing into governments - but governments have a long history of transmogrifying themselves into oppositions.
The Government is in something of a bind here.
With the elimination strategy now long gone, and vaccination rates very high, there's very little political risk to the opposition of calling for greater liberalisation.
Last year, the Covid picture was fairly binary: you'd either eliminated the virus or you hadn't. If the opposition called for something ridiculous, they were duly ridiculed with evidence from overseas.
This year, as the world transitions to something resembling post-pandemic life, the picture is far more grey.
Her Covid rule of thumb abandoned, Ardern might return to the electoral rule of Clark and Key: MMP elections are always close - and they're always won in the centre.