I think this is a simple left/right factional thing.
Clark was of the liberal left of the Labour party; Goff is from the more conservative right of the party. So is Mallard, and so is George Hawkins. Who are these two in the greater scheme of things? Mallard has written of his dislike of Carter on the labour blog quite a few times, and Hawkins was mentioned in the letter as someone likely to be "replaced" in his electorate by the EPMU faction.
Carter is certainly of the left, and is probably cringing at the possibility (extreme that it is) of having to work with Winston Peters next year as Labour's "go to" man for a coalition. I don't imagine an old conservative such as Winston and a gay liberal such as Carter get along very well. I could be wrong.
Carter is probably looking at the polls and thinking Labour's only chance is with Winston as a Goff-led party is unlikely to poll well enough to need just the Greens. After all, MMP elections are almost presidential in nature and so a Goff v Key contest is not really one at all. Carter would want a left-wing government, rather than a centre-left one. He has a leader from the right of the party; he sees the socially conservative/reactionary Winston as the only option for Labour; and he writes of the left-wing union bloc trying to overthrow another Labour MP from the right - George Hawkins. He dislikes the right-tinged direction of the party under Goff, evidenced by his comment on the choice on cashing in the fourth week leave.
Is Carter right in his comments about Goff? Well I'll leave that to Clark hagiographer, Brian Edwards. If these comments didn't come straight from New York, then I suspect they came from New York via Labour in Wellington.
Q. Is he right that there is widespread dissatisfaction in the Labour caucus with Goff’s performance as Leader?
A. My understanding is that there is widespread dissatisfaction with his performance in the polls.
Q. Is Carter right that a majority of the Labour caucus doubt that Labour can win the next election?
A. That is my information.
Q. Doesn’t the unanimous caucus vote to suspend Carter indicate that the entire caucus is behind Goff?
A. Not at all. Anyone who voted not to suspend Carter would effectively have been declaring that they agreed with his view that Goff could not hope to win the election. Anything other than a unanimous vote would have had the Press Gallery hunting to find the disaffected.
Q. Can Goff win the next election?
A. Probably not.Q. What chance has Carter of winning Te Atatu as an Independent or Independent Labour candidate?
A. None. Labour voters are Labour voters. Their loyalty is first and foremost to the Party.