So, the Labour Party now has its fifth leader since Helen Clark's resignation after the 2008 election. Why has this latest change happened? Three opinion polls in the past week have placed Labour under 25 per cent. In other words, the Labour Party is heading for an iceberg and a change of course is desperately needed.
The worst-case scenario is that Labour suffers its worst election defeat ever - worse even than the 25 per cent it got at the 2014 election. Andrew Little, as a list-only candidate, may not make it back into Parliament if Labour's election result really dives and its seat allocation is taken up entirely by electorate members. As the party's leader must be a Member of Parliament, Labour could have been left temporarily leaderless after the election. And no one in the Labour Party caucus would have had a legitimate claim to the post of prime minister in any post-electoral negotiations.
Winston Peters could potentially have claimed the mantle as leader of a new government. That's the worst that could have happened. At the least, it was clear that Little's profile was not working for the Labour Party. A couple of years ago, Labour was passing the 30 per cent level. They should have grown from there in the polls as voters became tired and disillusioned with the incumbent government.
Instead, Labour's polling was going down, and something needed to be done before the polls dived even lower. If Little had remained in place, reporters would have questioned his leadership anyway, making that a distraction right up until the election. So, Little has done the risky but honourable thing by standing down. It is characteristic of him to be honest and direct with us in announcing his decision.
It is clearly undesirable, though, to have a change of leader so close to an election. It not only looks desperate; it is desperate. With the change of leadership to Jacinda Ardern, then, how will Labour fare?
Ardern has been ahead of Little in preferred prime minister polls for some time. Although many people feel she lacks depth and experience, she is very popular.
She presents the party's policies and values clearly and authentically. At 37, she is young to become the Leader of the Opposition. And she now faces the prospect of pre-election leadership debates head-to-head with the much more experienced Bill English. But then, as a protege of Helen Clark, she will have seen how it's done.
Today's spill is clearly not the best way for her to have acquired the leadership, however. It would have been preferable to contest the leadership after the inevitable defeat at the coming election.
The Labour Party's rules require that a new leadership election be triggered if the leader "fails to obtain the support of 60 per cent plus one of the caucus membership in a vote held within three months after a General Election". So, her leadership may still be tested after the election anyway, especially if things don't improve.
The pressure is now on Ardern to lift Labour significantly in the polls, or her political career is at risk.
In her first speech as leader, she declared that Labour is about to run "the campaign of our lives". Indeed, it could be "do or die" for her and the party. Labour has been squeezed out of its traditional role as the "broad church" representing the left, thanks to growing pressure from the Greens and NZ First on either side, and an unusually popular centre-right opponent. In the long term, Labour is in danger of becoming a victim of the kind of political fragmentation seen in other proportional-representation systems in Europe, such as France and the Netherlands.
Ardern will now have to prove herself as the new Leader of the Opposition, and even as the next prime minister.
She and the new deputy, Kelvin Davis, will have to establish their profile for the voting public. And the party as a whole will have to get its policy and values messages out to the public, putting the distraction of the leadership spill behind them. And they have less than eight weeks to do it.
Public opinion these days is volatile and rife with discontent.
Will Labour's big risk pay off with a boost in the polls? If it does, will that last through till the election? I won't risk a prediction. One can only wish them luck.
Associate Professor Grant Duncan teaches political theory and New Zealand politics at Massey University. Views expressed here are the writer's opinion and not the newspaper's. Email: firstname.lastname@example.org