So, ACT is clearly at the extreme neoliberal/unstable end of this spectrum - both politically/economically and in terms of internal turmoil (the precise details of this clusterfuck from about 2002 onward being pretty well known, but memorably featuring the Nat-backed ouster of Hide by Brash, the earlier Roy-attempt at Hide, the full-blown civil war which accompanied that, ongoing (and very public) criticism from Roger Douglas of Hide's vibe, various rumblings against Richard Prebble ... and so on and so forth), these guys really are the apex and eminent case-study of the linkage between neoliberal vibes and flawed/tumultuous internal structures.
Then there's the Nats. Won't go into the details (there's seven decades' worth to countenance, with it getting particularly bad following the end of Muldoon), but it seems like the Born to Rule party is in an almost perpetual state of squabble about who, exactly, was born to rule whom. Memorable examples include attempted uprisings against Muldoon, the neoliberal plot against Jim Bolger which produced Shipley, the ouster of first Shipley and then her successor, English; and then in a fit of revenge, English leaking a whole lot of emails in order to torpedo Brash, thus leading to Key. And from Key unto either Collins or Joyce but they haven't finished duking that out yet.
What the National Party's vicissitudinal internal fortunes betray is that the more neoliberal a party gets, the more volatile its internal situation becomes.
Following on from this is the Maori Party. A Caucus of 3 MPs of which 2 are Leaders doesn't leave much scope for leadership squabbles I would ahve thought ... but apparently not. Again. They furthered a neoliberal agenda in concert with the Nats, and found themselves with first a Hone- and then a more generalized leadership problem.
Somewhere in the middle, we have the Labour Party. Mr Finlayson is correct to note that there do seem to be quite a few white ants in amidst the red ones, with specific dishonourable mentions including everybody subsequent to David Lange (seriously - how many leaders did they have between Lange and Clark, and for how long?), and a humourous side-note for Phil Goff's attempted "Chicken-Coup" of Helen Clark in the mid-1990s. Once again, there is a clear pattern. As teh party found itself becoming one of the underpinnings of our neoliberal paradigmatic consensus, its internal volatility increased. Up till the Clark years, at any rate. Quasi-social-democracy and winning elections is apparently something of a salve in this regard
Now at the complete opposite anti-Neoliberal/relatively stable end of the spectrum, we have The Greens and NZ First.
I'm going to chuck the Greens down first, for two main reasons: Mike Ward (former Co-Leader of the forerunner Values Party) and Nandor Tanczos. Admittedly it wasn't a traditional sort of leadership squabble, as the previous incumbent had quite literally died in office, but either way there was a contest, somebody wound up having to stand aside, and in addition to losing two well-recognized Parliamentarians, Mr Ward had to be lent on in order to be made to give up his entitlement to enter Parliament as next on their List. Clearly, "sustainable" economics is not negatively correlated with a sustainable interior position.
Anyway. I know I'm frenetically biased as all hell, but I'm chucking down NZ First last. As both the most stable (for the last decade and a half, at least) and arguably the most anti-neoliberal of the main parties. The only time we've had a leadership coup ... it was back in 1998, and was an arguable result of getting *much too close* to the whole neoliberalist vibe. And never was Tau Henare to darken our doorstep again. (The resultant Mauri-Pacific party failed even harder than the present Maori Party combined with Taito Philip Field's NZ Pacific party) Ever since then, we've been remarkably stable. *quickly runs to check history of Yugoslavia*
So yeah. There's my response to Chris Finalyson's "Unauthorized History of the Labour Party". All six main parties ranked on a spectrum from most-volatile/neoliberalist down to least-volatile/neoliberalist. It's pretty telling that it's the same spectrum, don'tchathink?