Act's flagship "three strikes" policy was knocked down by a curve ball that the party threw itself.
The party campaigned that 78 lives would have been saved by three strikes, and lined up a row of coffin lids outside Mt Eden prison to symbolise this.
But yesterday the Herald reported these claims are wrong when applied to the amended form of three strikes that has been introduced to Parliament as part of Act's governing agreement with National.
In its present form, it would not have struck out a single one of the 420 lifers in New Zealand prisons.
How could Act's information be so misleading? Act's David Garrett based the 78 killers on information from the Department Corrections that said there were 78 people convicted of murder or manslaughter who had three previous convictions for "serious violent offences".
The list of "serious violent offences" Corrections based this on is very broad - three pages long. It includes crimes like common assault - what you would get charged with if you shoved someone - that carry a sentence of no more than one year in prison.
Three strikes was never going to be palatable with a criteria that could see someone get a life sentence for three common assault convictions (essentially "three shoves and you're out").
Knowing this, Act tightened the criteria to a group of the more serious offences like rape, murder, aggravated assault - but did not get Corrections to adjust the "78 killers" figure. Act has just kept using it, without any qualification.
The figure became further outdated when changes were made as part of the agreement with National to introduce it.
Instead of letting three strikes go in as its own bill, Act agreed for it to be merged with National's hardline measures in the Sentencing and Parole Reform Bill, believing it would help its chances of being passed.
But it has produced a heavily diluted version of three strikes.
National's version defines a strike much more narrowly: not only does it have to be one of the specified offences, but you have to have been sentenced to a prison term of five or more years for it to count as a strike. Not even RSA killer William Bell or samurai sword killer Antonie Dixon have this sort of form.
The misleading figures are embarrassing for Act and damage the credibility of three strikes.
National only agreed to introduce three strikes, and has reserved judgment on whether to support it beyond the select committee hearings.
In the merger with National's measures, Act has lost control over three strikes: its identity is being confused and it looks more unworkable by the day.
Garrett wondered aloud last month if National was being "Machiavellian" with three strikes, and setting it up to fail. By using misleading figures, Act may have helped them along.