It could have all gone horribly wrong for John Key during
the leaders' debate in Christchurch last Tuesday evening.
Had David Cunliffe known the answer to Mr Key's attempt to
catch him out on the detail of Labour's proposed capital
gains tax, then Mr Key would have looked a bit silly -
especially as the answer he had was wrong.
But Mr Cunliffe did not know the answer to Mr Key's question.
In an instant it was obvious the Labour leader was
On such moments election campaigns can turn.
This was one those moments.
Mr Key took a punt. But it was thought to be a pretty safe
National believes Mr Cunliffe does not bother to get on top
For him, a capital gains tax is a means to satisfy the Labour
Mr Key's question more than did the trick.
It shifted the debate about the tax from arguments about its
benefits in terms of fairness and shifting money into
productive investments to questions about detail and its
impact on middle New Zealand.
As one sage observes of Labour's crusade for such a tax:
Everyone likes the idea, but no-one wants to pay it.
National had a field day for the next 48 hours, highlighting
anomalies and contradictions in Labour's proposal.
Mr Cunliffe managed to prolong the firestorm by getting it
wrong again, this time on how the tax would apply to a home
inherited from dead parents.
Labour should have foreseen National's onslaught. It should
have devised a strategy in readiness to counter it.
But Labour may have been lulled into a false sense of
Labour's intention to implement such a tax was part of its
But National did not aim its heavy artillery at the tax at
Labour may also have thought it had already won the argument
by virtue of a broad consensus in the financial sector that
such a tax is long overdue and - as a result - National is
the one which is out of touch and the pressure has been on Mr
Key and Bill English to come into line.
Beyond issuing a 10-page backgrounder which added little that
was not already in the 2011 manifesto, there was no briefing,
press conference or attempt by Labour to spin its way out of
Already struggling to make any impact, Mr Cunliffe's campaign
has taken a potentially fatal knock.
With two opinion polls yesterday showing Labour marooned at
about 25% and National registering at 50% or more, the
election campaign may effectively be over.
The only question now is whether growing backing for Colin
Craig's Conservative Party will translate into actual votes
on September 20 and in sufficient numbers to clear the 5%
threshold - and thus allow Mr Craig to come to the
negotiating table with enough seats for National not to have
to entertain a deal with Winston Peters.
While it is too late to gift Mr Craig an electorate seat, it
is likely Mr Key will make some carefully worded statement in
the final week of the campaign giving licence for potential
National voters to tick Conservative.
The possibility of Labour being in a position to form a
government now looks to be virtually non-existent.
With two weeks still go, Labour's campaign is The March of
the Living Dead.
• John Armstrong is The New Zealand
Herald political correspondent.