But even a politician of Winston Peters' calibre is finding the going tough and - to borrow David Lange's famous observation of Jim Bolger - succeeding in only stirring up apathy.
This week's Herald-DigiPoll survey confirmed there is precious little breadth or depth of anger with National for Opposition parties to exploit.
They keep trying, in part because that is one of the functions of Opposition and in part because they want to believe for the sake of their collective sanity that the next semi-crisis or mini-scandal to afflict National will be the one that breaks the camel's back and sets National's and John Key's opinion poll ratings on an irrevocable downwards slide.
If anything, the opposite is happening. Following an indifferent 2013, John Key is enjoying something of a second honeymoon with voters. In part, that is down to his unashamed pragmatism. Voters know if there is a problem, Key will fix it - and probably before they have even started squealing about it.
Key may have lost voters' trust on peripheral issues like the GCSB. On the matters that actually impinge on people's daily lives, however, Key has ensured he is swimming in the stuff.
Key's and National's stunning poll ratings are also down to something else - the clear signs that the economy is now growing at a reasonable pace at last.
When it comes to the things that really matter to voters - be it the economy, cutting crime, boosting hospital services or whatever, National has made sure it has the basics in order.
That is why there is palpable frustration in the Beehive that National's projection of an image of competence keeps being blurred by unwanted static, the latest examples bring the respective maelstroms surrounding the actions of Judith Collins and Hekia Parata, who this week made an absolute botch of her handling of allegations of misspending by a subsidiary of Te Kohanga Reo National Trust.
But voters do not seem to care about these blots on National's landscape. And come September, nobody will be talking about whom Collins had dinner with in Beijing. Or how Parata could go to bed saying one thing and get up the next morning mouthing the exact opposite.
In Collins' case, Labour's Grant Robertson has done a splendid job in not only vanquishing one of National's most formidable performers but also citing her as an example of what Labour refers to as National's "crony capitalism" by which National allegedly uses the instruments of the state - be it the tax system, bureaucracy or whatever - for the benefit of its "rich mates".
The "crony capitalist" labelling - designed to drive a wedge between National and middle-income and upper-middle-income voters who possess a conscience - has so far been a flop.
The same has been the case with David Cunliffe's similar exercise in wedge politics. He has also sought to syphon off the same segments from National by appealing to their social conscience with his talk of little else than income inequality and child poverty in his speeches, while carefully stressing those voters, comfortably off as they are, will not be socked with the tax rises needed to provide relief for the poor.
It is on income disparity, the cost of living and wages growth (or rather the lack of it) that National is vulnerable and where Labour until now has sought to fight the crucial debate on who is best to run the economy.
But it has been a holding operation for Labour. National is delivering growth which - it will argue - will begin to remedy the very things Labour has been highlighting.
Cunliffe has known all along he would have to confront National's strengths in economic management. He relishes the opportunity.
This week, he began the battle with promises of accelerated depreciation and suspensory loans for the forestry industry. That may not have grabbed the headlines, but if you are promising a revolution in how the economy is run, then the revolution has to start somewhere.
Cunliffe not only articulated his vision of a "value-added" economy, he detailed for the first time how that vision would be applied in a particular sector of the economy.
To watch Cunliffe extol the virtues of what he calls "intelligent hands-on" economic management is to witness the Labour leader at his most confident and self-assured best.
One of the reasons he has won the hard-earned respect of those on Labour's left is that Cunliffe has been consistent throughout his nearly 15 years in Parliament in his favouring a far more interventionist approach. It is also an approach which would go much further than Labour's "soft" intervention of the Clark-Cullen years.
In that respect, Cunliffe's approach to running the economy would be the most radical departure yet from the Roger Douglas-inspired economic orthodoxy - something that Cunliffe scathingly dismisses as "trickle-up economics".
A politician arguing the need to add value to a raw product rather than simply increasing the volume of that product is hardly new. Just recall Mike Moore's promotion of his lamb burger.
National is thus dismissing Cunliffe's approach as a return to the failed policies of the 1970s. What is different in Cunliffe's case is that he has had the time and the intellect to produce an integrated, cohesive and comprehensive blueprint for a more planned economy, one which would see much greater development of partnerships between Government and sector groups and Government and regional councils with potential new jobs the driving factor.
In what seemed to be a clever piece of political choreography, the day after Cunliffe's forestry announcement, Rotorua's Red Stag Timber said that, if implemented, Labour's policy would be the "clincher" for a $120 million upgrade of the company's plant.
The irony was that, like John Key's trip to China, Cunliffe's forest policy package was pushed into the shadows partially as a result of Labour rounding on Collins and Parata.
Annoying as that might be for Key, he can afford for it to happen. Cunliffe cannot. Labour has to get its priorities right.
