What’s a small political party like the Greens to do?

The difficulty here is what political scientists call the "unity-distinctiveness" dilemma.

It’s counterintuitive, but a change in government this year could present an existential crisis to the Green Party.

How can this be, given that 2017 offers the best opportunity the party has ever had to share in power? If power is the ultimate object of politics, isn’t the prospect of actually being in government the fulfilment of years of promise?

Well, yes. But the history of small parties in this country is not encouraging.

Since the advent of MMP, no such party has become the main support partner in government in one election and then emerged at the next with more than 5 per cent of the vote.

In fact, this electoral trauma occurs with such regularity that it could almost be considered the iron-law of New Zealand politics. Consider the following:

Between 1996 and 1999, NZ First went from 13.35 to 4.25 per cent.

Between 1999 and 2002, the Alliance went from 7.74 to 1.27 per cent.

Between 2002 and 2005, United Future went from 6.62 to 2.67 per cent.

Between 2005 and 2008, NZ First went from 5.72 to 4.07 per cent. Having consolidated the Centreright vote behind it in 2005, National has not had to govern with the support of any party with a significant number of seats. It instead relies on ‘‘zombie’’ parties based around the retention of one or two electorates but no real national following. Even then, however, comparing these parties’ results between 2008 and 2014 shows a consistent pattern.

ACT has gone from 3.65 to 0.69 per cent.

The Maori Party has gone from 2.39 to 1.43 per cent.

United Future has gone from 0.87 to 0.22 per cent. The difficulty here is what political scientists call the ‘‘unitydistinctiveness’’ dilemma. This refers to the tension of forces that tears minor parties apart when they agree to share power with a larger party.

Picture some medieval criminal being drawn by two horses and you get a rough idea about what this is like.

One of the horses is called ‘‘Unity’’ and pulls the man in the direction of supporting the larger party it has pledged to put in government. This horse is strong because taking responsibility for the governance of the realm means maintaining some measure of communion with the senior partner. How can you justify keeping in power a party that you continually disagree with or attack?

The second horse is called ‘‘Distinctiveness’’ and pulls the man in the direction of retaining the independent identity for the smaller party.

This horse is equally strong because the junior partner’s voters and activists will inevitably be disappointed to see their champions line up to defend compromises at odds with party ideals.

When a small party becomes controlled by the interests and the agenda of the larger one, what’s the justification for its separate existence?

Following the failures of the 1996 to 1998 National-nz First and the 1999-2002 Labour-alliance coalitions, small parties have tried to square the circle by shying away from fully fledged coalition deals with the party of government.

Support is limited to confidence and budgetary votes in exchange for Government support for a few pet projects. Smaller party MPS are allocated less consequential ministerial jobs and remain outside of Cabinet which, in theory, allows them to attack Government initiatives that fall outside their portfolios.

But this hasn’t worked, of course, as evidenced by the carnage listed above.

In any event, the Greens don’t seem to have an appetite for the ‘‘in the Government, but not of the Government’’ conceit of recent years.

From the signing of the Memorandum of Understanding last year, to the ‘‘Best Friends Forever’’ strategy, to having Andrew Little at its conference, to contesting the Mt Albert byelection, it’s pretty clear that the Greens want to be part of a solid coalition rather than an artificial add-on to a Labour Government.

This was the approach that the Liberal Democrats took to the coalition government that ruled Great Britain from 2010 to 2015. When its poll ratings tanked, it responded by touting its ability to infuse the Government with a liberal agenda, reasoning that voters would appreciate its constructiveness and cohesion in government.

They didn’t. The Liberal Democrats went into coalition with 57 seats and won just seven at the next election. Like so many smaller parties, the effect of being in government was toxic to their voter appeal.

There has been some suggestion that, if push comes to shove, Little may spurn the Greens for NZ First. Having been jilted at the altar twice before, this would be the occasion for much angst for Green MPS.

But as hard as it would be to take, maybe it would be the best thing that could happen to them.