KEY POINTS:
It's 40 years on from the grandiose student "revolutions" of 1968, most boisterously in Paris and at the United States Democratic presidential nominating convention. The real revolution was quieter. The Greens, who meet in conference this weekend, are heirs to part of that quieter revolution.
A focal point for the dissidence of 1968 was the American war in South Vietnam to stop the communists taking over.
New Zealand was a minimalist ally in Vietnam. Nevertheless, that stirred protest. The troops who fought there - in effect, in defence of good trade relations with the United States - bore the policymakers' stigma. They were short-changed by an embarrassed and divided country.
Only now are they to be properly recognised alongside the veterans of other wars, by way of a formal apology tomorrow from a government composed in large part of veterans of the protests. Time improves perspective.
Underlying the 1968 unrest was a shift of values away from the moral strictures and materialism of the 1950s. It was the apogee of social democratic triumphalist belief that a truly equitable society could be built by collective action. Just beginning to emerge was a demand that that idealised society would take more notice and care of the natural environment.
Four years later, to the surprise of the political Establishment, a new party called Values burst into the binary politics of the 1972 election.
The ideology of the Greens, into which the Values party later morphed, was thus framed in the debates that surfaced in the late 1960s - much as the Labour leadership's ideology was framed by other arguments of that era.
The challenge for both Labour and the Greens is to reframe the ideologies so they are attuned to the values of later generations.
Scoffing at John Key for not remembering if he was for or against the 1981 Springbok tour is irrelevant to anyone much under 50, for that issue evaporated not long afterwards.
Is there a parallel for the Greens?
Now that nearly everyone seems to think climate change is a real issue (though also think action should be costless), you would think not.
But the Greens bump along in the 5-8 per cent band, election to election, poll to poll. They have not exactly set a fuse for revolution.
Is there a risk for today's Greens that Nick Smith is right to claim for parties of the right the environmentalist mantle of the future?
When the Greens this weekend debate the broad parameters of their post-election positioning, can it include being a support party for a National-led government - voting with it or (as with Labour now) abstaining on confidence and supply?
The short answer is very likely to be no - that the Greens cannot be the reason there is a National-led government if Key can't otherwise get the numbers and turns to them. There is too strong a "left" contingent in Greens' ranks to get consensus for that. And their core vote would be displeased.
So most likely the Greens would at most contemplate specific deals with National, as they have done with Labour-led cabinets since 1999.
Green politics has not followed the same trajectory as early Labour politics. Labour adapted its programme and over time its politics become mainstream: 40 per cent-plus of the vote.
Environmental politics has become mainstream by (partly) greening Labour and National. The Greens have stayed at the margin, as did the true-believing socialists when Labour rose.
The Greens would say "vanguard", not "margin" - that is, they constantly re-chart the path the big parties eventually edge down. They point to a new cohort of young Green (and small-g green) activists with a modern agenda that can appeal to younger people's ideals. More immediately, where do the Greens stand on the greenhouse gas emissions trading bill?
For the moment, opposed. They say David Parker's amendments draw too many teeth. That means, given the Greens' influence with the Maori party, the bill probably fails even if Winston Peters backs it, unless there is an imaginative compromise or National reverses out of its new intransigence.
Peters has reason, as Foreign Minister, to come on board. If the bill fails, the impact on this country's reputation abroad will make the negotiators' task harder in talks for a post-Kyoto agreement at which New Zealand needs special recognition on forestry and agriculture.
National seems not to have factored this in - nor that business faces another year of uncertainty (which affects investment decisions), nor that Parker's amendments go a long way towards meeting most of National's objections, nor that Australia's very different emissions profile greatly complicates linkage to its trading scheme.
It is not pretty politics. But neither was politics pretty on the barricades of 1968.
Then, the prosperity consensus of the 1950s was being torn apart. Now the prospect of an environmental consensus looks still to be a long way off.
If so, there will be space for the Greens for a while yet.
