Appropos of nothing much, here is a summary of why each of New Zealands political parties have authoritarian tendencies - even the ones you wouldn't expect to:
New Zealand First get their core support from grumpy old gits who feel that life has given them a raw deal and no-one else should have any fun.
National divide NZ into the worthy (white middle class males) and the unworthy (everyone else) and feel the best interests of the former are served by clamping down hard on the latter.
ACT were founded on the basis of liberal social policies and free market economics. However, they have never succeeded in convincing the poorer 90% of the populace that they wouldn't lose out big-time from an unfettered free market. As a result, they've dumped the "liberal" bit for a dose of good old-fashioned bigotry.
United Future take their ideology from God and "the man in the golf club". Both of whom have no time for gays and pinkos.
Labour, being mostly teachers and lecturers, see the rest of us as a bunch of naughty students. Plus, they are terrified that enough bigoted old gits will forget who keeps them in booze and fags and run off to vote for a right-wing party.
Jim Anderton is just anti-fun - hence that's the policy of his personal party, the Progressives.
The Greens are mostly pretty liberal - except that some of their aspirations, like banning motor cars, are not going to be popular with many people and will need a firm dose of the jackboot (is there such a thing as a jack sandal?) to implement.
And one that doesn't get MPs elected:
Libertarianz believe in personal freedom above all else. However, they also believe that unfettered use of private property is the highest personal freedom. Consequently, while they oppose state funded stormtroopers, they're perfectly happy for people and corporations to form their own private armies.