Labour and the Greens have again in recent weeks been banging their heads against a wall: trying to dislodge John Key from his supra-political perch.
As ever, Mr Key has deflected them by a combination of bland assurances, partial retreats and counterpunching - with collateral damage to innocents, including the Red Cross and Green MP Mojo Mathers.
That keeps him centre-stage, not as villain (which he is only to those already turned off) but as victor.
Why, then, do Labour and the Greens (and Winston Peters, but with a subtler edge) keep putting him up in lights? Why attack the Government's strongest presenter?
Would it be more effective, some ask, never to question Mr Key in Parliament and attack only the weaker links?
Opposition parties face a similar conundrum over next week's Budget. Bill English will present reassuring, even bullish (as in a speech last weekend), numbers. He signalled last Thursday extra money for some areas where the Government is vulnerable - health is an obvious candidate - to blunt opposition parties' attacks and deprive them of political oxygen.
Labour's response, as the senior (in two ways) partner in the opposition duo (sometimes trio), is in two parts: long-term strategy, looking out 20-30 years, and short-term tactics.
The strategic dimension is a search for a new paradigm to replace the baby-boomers' paradigm that essentially drives current policy, though Mr English has made some major tweaks, such as "social investment''.
Labour shadow finance minister Grant Robertson is seeking "new settings, a new system to guide sustainable development and wellbeing'' in a highly globalised world, reaching out to the 20-somethings generation. He liberally uses the word "investment'' to explain his aims.
Mr Robertson has plugged himself into the 20-somethings who he thinks are as different from their parents as the baby-boomers were from their parents in the 1960s, which implies a major policy shift at some point.
One big change already under way is "work'', which takes, and will go on taking, many new forms beside the 20th-century employer-employee arrangement. Stability and security are likely concerns as 20-somethings graduate to family life through the next 10 years.
National, including Mr English, scoffs at Mr Robertson's "future of work commission''. But Australian conservative Prime Minister Malcolm Turnbull is running that phrase in his election campaign. The Foundation for Young Australians has put together a useful booklet on the implications.
And here the Ministry of Business, Innovation and Employment is quietly exploring it (under a different title).
A second Robertson focus is standard Labour - more social assistance, education and health spending to ensure "shared prosperity'' - but with a twist. Mr Robertson pitches this as "housing first''.
This is not just a genuflection to Phil Twyford, arguably Labour's most effective shadow minister.
It recognises that the house - good or bad, long-tenured or just for weeks or months - is a core element in a child's upbringing, health and capacity to get educated, then, as an adult, to earn an income and fully participate in society. And, along with "work'', the house contributes to adults' capacity to run a strong household in which they and children thrive.
A third Robertson long-term focus is economic diversification. More tourists, now a flood, keep us low-waged.
But in debating a Budget and contesting an election, long-term thinking is too pointy-headed for most voters.
They want a sense of how household finances will be in a year or two. The older the voter, the more that short-term rules.
That takes Mr Robertson to a range of do-it-now proposals such as more infrastructure investment, the state quickly building good houses for less-well-off buyers and renters and backing social enterprise and youth entrepreneurship.
A big focus will be to make up the gap in health spending which has matched general inflation but not technology inflation and demographic changes in total numbers and age distribution. Health shadow minister Annette King ran an interest groups "summit'' on it last week.
Another focus is on investment in children. Labour (Mrs King again) was way ahead of National in 2010 but didn't push it in 2014 and Mr English has been catching up.
But both the long and short will come to nought if Labour can't present a visible alternative government to voters at next year's election - that is, a strategic and substantive collaboration with the Greens, which was lacking in 2011 and 2014.
This far out from the 1999 election, Helen Clark, in opposition, went to the left-wing Alliance conference. Some thought that would taint her. Instead it showed voters a government in waiting.
Some in Labour and the Greens have suggested Andrew Little could emulate that at the Greens' conference at Queen's Birthday Weekend. Some think there is some possibility he might.
If so, it could be his biggest step as leader. And Mr Robertson might get to write a Budget.
Colin James is a leading social and political commentator.
