Age is not an immutable characteristic. Treating children differently to adults is not the same as treating people differently based on race or sex. And 18 years is the generally agreed-upon age at which a child becomes an adult.

For most New Zealanders, the idea of 16 and 17-year-olds voting defies common sense. Large majorities of people surveyed reject the idea. Letting kids vote is less popular than letting prisoners vote.

Of course, there is increasingly little room for common sense in New Zealand's appellate courts. Not, at least, when the opportunity for the promotion of liberal opinion is concerned. Our justices are no longer so shy of broad political questions that touch upon subjects not usually reducible to legal reasoning.

And so it has come to pass that the New Zealand Supreme Court has ruled that the Crown has failed to justify restricting the franchise to adults. This has prompted the Labour government to respond, which it will apparently by endorsing a move towards a lower voting age. The court has, therefore, set the agenda on an inextricably political question.

It is a rarer and rarer thing for our justices to refuse involvement in political questions when it comes to the preoccupations of the chattering classes. The best that can be hoped for is a reluctant refusal to grant relief paired with some obiter dicta about where the court's sympathy lies. Those comments crack the door open just that little bit further, of course, and provide something for the next case to build upon.

This is not all the fault of the courts. Judges are only human and there is nothing more human than being tempted to use the tools at your disposal to achieve the outcome you want. Some blame lies with the elected politicians who have given the judiciary these tools or, at least, have permitted their use.

Ambiguous laws promote judicial activism. They create a permission structure for the judiciary to exercise personal discretion to the act interpretation. Both of our main political parties have often passed legislation leaving much to be desired in the clarity department.

The New Zealand Bill of Rights 1990 is itself an example. Do you think many of the lawmakers back then would have agreed that they were opening the door to a decision like that of the Supreme Court today? They passed the law, nevertheless, despite this being an entirely foreseeable consequence.

Well, there's no changing that. If there is a change of government next year, however, it would be good to see more willingess to challenge the legal establishment. An effective agenda here would involve:

• Repealing the recent amendment to the law requiring the elected branch of the government to respond a judicial finding of legislation being inconsistent with the Bill of Rights.
• Add a new section to the Bill of Rights specifically stating that the courts have no jurisdiction to make decisions involving inherently political questions, particularly those where voters and representatives can be reasonably expected to resolve those matters.
• Add a new section to the Interpretation Act 1999 providing that no international treaty, agreement or other instrument will have any bearing on the interpretation of New Zealand except to the extent it is incorporated into legislation.
• Add a further provision that that legislation should be interpreted based on the understanding of their meaning at the time they were enacted.
• Perhaps most controversially, amend the Constitution Act 1986 so that a judge's flagrant unwilingness to carry out the will of Parliament provides grounds for removal from office.

Law faculties would absolutely hate this as, would of course, the judiciary. But the time has long since passed where the democratically accountable branches of the government flex a bit of muscle. And if the courts are bent on drifting into politics then they can hardly complain about politics drifting into the courts.