In contrast, politicians with strong convictions don't listen to focus groups very well.
For the last three years the groups have been making excuses for the government.
The global financial crisis. Christchurch. Expectations have been low and National has met them.
Someone in a focus group chiselled the words John Key uses repeatedly now: "Uncertain and difficult economic environment."
The excuse for the double downgrades, the excuse for putting up GST, the excuse for higher unemployment.
A few years ago, before the National Government announced they would sell down our power companies and Air NZ, a pollster working for an outside company told me what focus groups thought about asset sales.
"They're totally against it." Why don't you want them sold? "They already belong to us. We've sold too much already."
So do they think the assets would be sold eventually? The groups grumbled they probably would go. And would you change your vote to stop it happening?
"Oh yes, it's terrible." But John Key says it's okay. "Oh, well that's okay then."
Which is why National has pictures of John Key on its hoardings this year and Labour features the statement "No Asset Sales".
The point for Labour is to move past the ready-made excuses the Government is relying on for non-performance over the last three years and look ahead to what is planned for the future.
National's hoardings are less definitive about their promises. They can't point out their achievements, so resort to fudges about "building" a future. "We will" rather than "we have".
So just as focus groups wouldn't have liked National's asset sales, you can be sure no focus group told Labour: what we need is a capital gains tax, and put up the age of retirement while you're at it.
What hasn't worked for Labour over the last three years has been the attempt to construct a counter-factual that persuades voters that the country would be better if only things had been done differently.
Labour has begun to show convincing ways to break out of the story already constructed for them and set an agenda for the election: Make it about tough decisions and the strength to look to the future. In a room somewhere, a small group of people will be discussing whether boldness and tough decisions beat excuses.
John Pagani is a former adviser to Labour leader Phil Goff and former Progressives MP Jim Anderton. He blogs at johnpagani.posterous.com