This will upset The West Wing tragics among us, but it's wrong to call Labour's method of electing its leader a primary. It creates the impression of far greater democratic participation than the reality.
A more accurate analogy in US politics is a caucus, a means of intra-party voting that attracts a smaller, less representative, coterie of hardcore activists.
Take two early contests during the 2008 Democratic nomination battle between Barack Obama and Hillary Clinton: in South Carolina, a state with a similar population to New Zealand's, more than half a million people voted in the primary; in Iowa, with a population of just over three million, 15,000 diehards participated in the caucus.
According to figures leaked to the media, only around 5000 members took part in the election of David Cunliffe in 2013. It may seem an improvement on MP-only ballots, but the process falls way short of earning the title "primary".
The caucuses that more closely resemble Labour's approach are widely considered outmoded, undemocratic and politically fraught in the US. Politicians in Nevada last year moved to abolish their state's caucus because it "disenfranchises voters", advocating a primary instead.
The Washington Post reported in February moves by moderates in the Republican Party to abolish caucuses altogether because they give rise to "more extreme candidates" like evangelical zealots Mike Huckabee and Rick Santorum who won Iowa in 2008 and 2012.
With so few members, the process is wide open to manipulation. For the cost of a second-hand Toyota Corolla, an unscrupulous candidate could pay for enough memberships to determine the outcome of the contest. In Australia, such "branch-stacks" are commonplace for far lesser prizes.
In electing a leader, there's a strong case that it makes more democratic sense to call on MPs - who collectively represent 600,000 voters, even at Labour's low ebb - than a handful of members exceeded in number by a medium-sized bowls club.
With fewer than 1 per cent of New Zealanders who support Labour given a say in who leads the party, except indirectly through parliamentary representatives, it is inevitable the election will produce victors from the activist fringe.
A genuine, mass participation primary could transform Labour and begin to reverse its slow, heartbreaking descent into irrelevance. If Labour voters turned out at the same rate as South Carolina Democrats did in 2008; 150,000 of us would cast a ballot. As well as being near impossible to fix, an election on such a scale would offer a superb campaigning platform and deliver a resounding mandate for whoever prevailed.
I'd like to hear how the leadership aspirants plan to revive the party beyond safe platitudes and empty buzzwords. Concrete steps that take on a machine that thrives on keeping the party small and tightly controlled, and gives Labour voters - not just the smattering who clear the bureaucratic hurdle of membership - a meaningful say in the party's future.
• Phil Quin is a former Labour Party adviser and a strategic communications consultant.