Such are the brutal realities of coalition politics. Parties either accept them - and become genuine players in the political game - or they reject them and remain political spectators.
It is really only the world's Green parties that struggle to accept these largely self-evident rules. As the ideological offspring of May 1968 (when the great counter-cultural uprising of the world's youth reached its zenith), the prototypical German Greens eschewed all political hierarchy in favour of "appropriate decision-making" - by which they meant "grassroots", "bottom- up", consensus-based democracy. And this was no mere rhetorical flourish: Greens really do believe the way they arrive at major decisions is every bit as important as the decisions they make.
All of which lays a heavy burden on Russel Norman and Metiria Turei. Rather than laying claim to portfolios that their prospective coalition partners in the Labour Party couldn't possibly agree to assign them (not without opening up huge divisions within its own ranks), the Greens co-leaders should be thinking about how to reconcile their fellow party members to the unavoidable compromises of coalition politics.
Because these are likely to be both numerous and unpalatable. On practically every economic and social issue that matters, the Greens have positioned themselves well to the left of Labour. That being the case, very few, if any, of the Greens' preferred solutions to the high dollar, unemployment, child poverty, homelessness, climate change and dirty dairying will win Labour's unqualified endorsement.
As a political party on its way to the treasury benches, the New Zealand Greens would be wise to learn from the experience of their German counterparts. Tumultuous gatherings on the model of the Bielefeld conference make for the most stunning political theatre, but the long-term consequences in terms of preserving ideological coherence, or even the enduring goodwill and commitment of the party rank-and-file, can be extremely debilitating.
Trotter is never one to use one word when one hundred will suffice, but he highlights a major potential pitfall for the Greens. Being vocal and highly principled in opposition is one thing. But having to compromise and be pragmatic in government is another thing again, especially if you are the minority partner in an MMP coalition government.
The only thing that Trotter omitted here were those three little words that brought Winston Peters undone between 2005 and 2005; baubles of office. Can the Greens resist them?