Out on the edge, how do you build your vote?

On the wings of our electoral system are two parties which claim the future. But they could hardly be more different futures and they could hardly promote them more differently.

The Greens want ecological harmony, humans linked to nature in economic as well as spiritual life. ACT instals the individual at the centre of the universe and insists true harmony comes from individuals following their best instincts.

The Greens believe in regulation to achieve their ends, ACT in deregulation.

The Greens have generally been better at getting support than ACT these past two years. Why is that?

This disturbing question will stalk ACT’s conference this weekend.

If Richard Prebble is true to form he will cite ACT’s 0.2 per cent lead over the Greens in last Friday’s poll. But the Greens have led by an average 2.3 per cent over the past 12 months. Not once since the 1999 election has ACT polled higher than its score then. It has averaged 4.2 per cent.

Since ACT won’t win an electorate seat, that is a bother. National supporters will probably once again come to the party to hoist it over 5 per cent. But that is no way to a long-term future.

The key to that future is to recognise explicitly what the Greens have recognised implicitly: that both are edge parties.

Of course, both think their futures so commonsense that one day the uninitiate will swarm to them. ACT once reckoned on half the vote. The Greens, slightly less immodest, have talked of 10 to 20 per cent.

But the Greens have pitched their message better. They have been more sensitive to their natural catchment and played to it.

So they have fluttering at their mast a rack of pennants: safe food, organics, conservation and ecological diversity, anti-free-trade, peace, youth, cannabis. Closest to the mast are the very true believers, fiercely dark green; tapering away in the breeze are lighter green people, a few (safe-foodies, for example) maybe as much blue as green on other matters.

These slivers of vote add up to more than 5 per cent in polling.

ACT has chosen a diametrically different course. It has principles and even publishes books to explain them, for example, last year’s “Closing the Gaps”. In parliamentary debate and in speeches these principles are a recognisable substratum.

But ACT’s popular face is quite different.

First, ACT is the scourge of scandal. That is very useful, in exposing the questionable Kiwibank’s commercial foundations, for example. If the government was ageing and not popular for other reasons, this tactic would drain votes. But it does not build ACT’s vote.

Second, ACT pushes some principle — on the Treaty of Waitangi or law and order, for example — in a manner intended to appeal to redneck voters who would otherwise vote Labour. But these voters, as the last election showed, do not like the economic and social policy principles.

And those who do like the economic and social policy principles do not like the populism. Unlike the Greens, ACT is not playing to its positional strength.

An edge party does not have to satisfy middle New Zealand to clear 5 per cent. It can focus on a smaller catchment.

But even then it must perform a balancing feat.

The idealists’ future will never arrive on a 5 per cent vote. On that vote the future can be grafted only in small amounts on to a big party’s centrist programme. And such incrementalism can split edge parties, as the German Greens and our Alliance, their radicals in revolt, have found.

On the other hand, even for an edge party, too much radicalism turns off softer fellow-travellers who may be needed for 5 per cent. Christian Heritage is an example.

The Greens’ polling has dropped by a fifth since the GM potato vandalism and promises of “sovereignty” for Maori. Such radicalism appeals only to the very darkest greens. Lighter greens have the rather green Labour party to switch to. So the pennants have been fraying at the ends.

Prebble understood the perils of radical excess when he dumped zero income tax and rescued ACT in 1996.

But too little radicalism loses the true believers. The question for Prebble this weekend is whether he has paid too little attention to the 2-3 per cent who should be his core vote.

For without them, ACT’s future is fragile.