By advocating for a controversial policy, Labour has managed to win public backing for it:
Once regarded as a political poison, public opinion has moved in favour of Labour's capital gains tax since it was announced three years ago and support for idea has moved well ahead of the party's own popularity, according a recent Herald Digipoll.
Numbers backing the policy, which is Labour's primary weapon to curb rising house prices, is particularly strong in Auckland where first home buyers have borne the brunt of those increases.
Its still not strong majority territory, unlike e.g. the health and education systems or the principle of progressive taxation. But for a policy long considered a "third rail" of New Zealand politics, its a significant shift.
This shouldn't be surprising - National and the Greens have been doing this for years (and Labour's adoption of the capital gains tax is in part because the Greens had laid the groundwork by pushing for it). But it ought to put paid forever to the idea that parties are just "logs floating in a stream" which must go with the flow of public opinion because they are unable to affect it. Weak parties are. But if Labour stops being scared of its own shadow and afraid of its left-wing heritage, it can actually change things, and build the majorities it needs to govern.