There are never any final battles in politics. No one should begrudge John Key his moment of triumph on Saturday but - as he will be well aware - the campaign for the next general election has already started.
A 48 per cent share of the votes cast was, on the face of it, an outstanding achievement. But we should bear in mind that fully two-thirds of New Zealanders eligible to vote did not give their support to National, either failing to register or vote, or voting for someone else.
This was not, in other words, a coronation. Not everyone loves Key. Yet we can already see the "elective dictatorship" syndrome in Key's claim that he has a mandate for asset sales, despite the incontrovertible polling evidence that the policy is opposed even by National voters.
The election campaign was at times an unhappy experience for Key. It revealed to his supporters, among voters and in the media, a politician whom many may not have seen before. The images of an uncomfortable and defensive Key, clearly irritated at being challenged and having to answer questions he would prefer to have ignored, will remain in the memory for a long time.
Nor is it the case, as some have suggested, that Labour's poor showing means that the next election is already a lost cause. We should not forget that, in 2002, National's share of the vote dropped to just 22 per cent, yet three years later, under the leadership of that "strange fellow" Don Brash, National very nearly pulled off a win.
None of which means that there is any disguising the mountain Labour has to climb if it is to mount a real challenge in 2014. The first casualty of their failure has been their leader - rough justice in a sense, since Phil Goff emerged from the campaign with an enhanced reputation.
The lesson that Labour must learn, though, is that elections are rarely won on the strength of a four-week election campaign. Labour worked hard through the recent campaign but they made virtually no progress in undermining the image that Key had projected over the preceding three years.
The truth is that Labour lost the election because they were, for most of the parliamentary term, an ineffective Opposition. They did not work hard enough. They left their run, such as it was, far too late.
Labour's new leader needs to think hard about the politics of being in Opposition. If they are to do better this term than last, there has to be a carefully planned, developed and staged strategy so that, by the time the next election campaign starts, the groundwork has been properly laid.
The first objective must be to help voters to look behind the smile and the photo opportunities, and to ask the hard questions about exactly what the Government is doing, what it has achieved, and - above all - whether the Prime Minister can be trusted to tell the truth.
The goal must be an electorate that is ready to examine Key's words much more critically, and media that do their proper job of ensuring that voters are properly informed.
A classic example will arise early in the life of the new government. Key has so far avoided giving a straight answer to concerns about the foreign ownership of the assets that he intends to sell - concerns that are hardly surprising in a country that has already sold a higher proportion of its assets into foreign ownership than any other developed country.
He hints that he will somehow ensure that shares in those assets will remain in New Zealand hands. Yet Key knows (and Bill English has tacitly admitted) that the trade agreement with the United States and others that is currently being negotiated in secret is almost certain to make it illegal to discriminate against foreign investors when those assets are sold.
The task of an Opposition is to make sure that, on this and other similar issues, the Prime Minister cannot simply smile and shrug - and make up an answer that doesn't quite mean what it seems to mean.
The Labour front bench must also think harder about how and when to launch policies that are needed but contentious - policies like a capital gains tax, raising the retirement age, and extending the emissions trading scheme to agriculture. Policies like this should not be launched at the last minute, leaving little time for them to be properly understood.
The policies that should appropriately be launched near or during the election campaign are those that will have a wide and immediate popular appeal - policies like raising the minimum wage or using the dole to subsidise youth employment.
There are, in other words, three stages in a successful campaign.
First, changing - through hard work and relentless pressure - the public perception of Key as a leader who can be trusted. Second, taking enough time, well before the election, to build support for policies that opponents can easily misrepresent. And third, launching vote-winning policies so as to generate momentum through the election campaign.
A new leader and a strategy like this could make for a very interesting election in 2014.