Dead rats and saving the brand

swiftly to coalition politics – or, as the faithful will say, selling-out.

Under leader James Shaw, the party has already reversed its traditional opposition to wakajumping laws, on the doubtful grounds that the new bill allows for expulsion of an MP from Parliament only if two-thirds of the caucus agrees to it. That makes no essential difference: it is still a charter for a leader to impose their will on a party.

Shaw has also given up the fight for a marine sanctuary in the Kermadecs, and here again he has surrendered to NZ First, the champion of the commercial fishing industry. Finally, the Greens seem to have gone soft on free trade deals, and here the capitulation is to Labour.

If the Greens are to keep any plausible distance from Labour and NZ First, they will need a staunch, activist-friendly leader. That is Davidson, not Shaw.

And it doesn’t really seem like Eugenie Sage either, another possible candidate for woman coleader. Sage’s strengths and interests are in more traditionally Green issues such as conservation.

Julie Anne Genter, despite her obvious political skills, doesn’t look like a leader who will imperil her own chances as minister to advance the causes of women and the bicycle lobby.

The Greens think they can avoid the curse of MMP, under which small parties in coalition wither and die. In fact, this danger is possibly greater for the Greens than any other party.

Jacinda Ardern threatens to steal the Greens’ thunder over poverty and climate change. She has staked her career on fixing the first and has said the second is the "nuclear issue of our age".

Ardern, however, is well to the right of the Greens on both matters, and is all too likely to fudge hard decisions. Does she really have the bottle to take on the powerful farming lobby? And just how will she deal with the predictable backlash that will come over policies that promise to "close the gaps"?

Davidson isn’t a minister and so has less personal stake in coalition deals or swallowing dead rats. Her job would be to keep the party true to itself and preserve the brand – for without the brand, the Greens will die.

The risk, of course, is that the Greens will split down the middle under the pressures of coalition. Ardern is a cautious centrist, and Peters is a deep-dyed conservative and is no more green than Steven Joyce is.

Being in coalition with Ardern and Peters could spell death for the Greens.