Sure, recent National Governments might have surprised voters post-election by introducing unexpected taxes, but voters make decisions by the contents of their wallets.
For many, Labour's tax plan comes with a giant asterisk.
"We're being totally clear that we may or may not introduce more taxes at an unspecified time depending on the view of a group of experts whom we haven't yet publicly identified" doesn't scream transparency.
Of course, whether they are trying to pull a swifty doesn't actually matter.
Maybe Labour does have an agenda.
And maybe it wants to earnestly consider policy with the full wealth of data and information available at Government level.
But it isn't the earnestness of their Working Group that matters to voters. It's perception that matters.
Labour has been desperate to assure Kiwis of its fiscal responsibility.
It signed off on Budget Responsibility Rules and rightly raged at Steven Joyce's arithmetic attack.
But it's an extraordinary gamble to make itself vulnerable to the kind of tax-and-spend criticism that has always dogged the left. And it has had nine years in opposition to work out a tax policy.
It could yet prove to be a genius political gamble. If Labour forms the next Government, it can take up the Working Group's recommendations and claim somewhat of a mandate.
A majority of voters may even support comprehensive capital gains. But if the left goes down on September 23, Labour should blame tax.
• Jack Tame is on NewstalkZB Saturdays, 9-noon.
