We can accordingly hazard an informed guess as to what has happened on the refugee issue. John Key's first assumption was that Kiwis would react adversely to the prospect of increasing the number of refugees we are willing to accept. But, as the television pictures have become increasingly harrowing, the focus groups have registered a decisive shift in opinion.
Kiwis, to their credit, seem to have reacted to the crisis with common humanity. They did not like to see themselves portrayed as selfish and stony-hearted.
John Key recognises that he got it wrong, and that he is taking some flak as a result. But he also knows that he can limit the damage if he can re-position himself quickly, without being accused of flip-flopping too obviously. A carefully choreographed and well-practised process of cautious change is therefore under way.
At one level, this sensitivity to public opinion is to be welcomed. A Prime Minister who is willing to admit on occasion that he is wrong and to adjust his position accordingly can be seen as an example of democracy in action. And who can complain if a politician changes his pitch when the polls tell him he should? It seems likely, for example, that the focus groups have delivered the message that people are a little tired of seeing so much of the Prime Minister as a "cheeky chappie" or "man of the people", which is why we seem to have seen less of that persona on our screens since the election.
The practise of deciding policy in the light of public opinion does, however, have its downsides. It may be used, for example, to conceal from a possibly sceptical or hostile public just how far and fast a given policy is intended to go.
John Key has occasionally revealed, perhaps unwittingly, how that can be done. In November 2014, for example, he was reported as advising Campbell Newman, the then Prime Minister of Queensland, that an asset sales programme could be made acceptable to public opinion if it was undertaken in stages, so that people were not unduly alarmed and could not see the end goal.
Using the results of qualitative polling can help a government, in other words, to identify techniques for manipulating public opinion so that it becomes more receptive to proposals that are initially opposed. Those techniques include proceeding by carefully calibrated stages, and interposing intermediate processes, such as the setting up of inquiries guaranteed to reach conclusions congenial to the government.
The readiness to track and follow public opinion may also, if it becomes too obvious, redound in the long run against the reputation of those practising it. Voters like to believe that their leaders are people of strength and principle and do not swing around like a weather vane.
A politician who says too often "you don't like that policy? Well, here's another one" can seem shifty and untrustworthy. And, once the impression is gained that a leader's statement cannot be relied on, and is always likely to change, an important element of leadership is seen to have been undermined and lost.
That sentiment is all the more likely to be felt when it is the country's concept of itself that is at issue. There will be many who believe that it is not the role of focus groups but that of the Prime Minister to identify and articulate the values we hold and to define who we are as a people.
Bryan Gould is a former UK Labour MP and former vice-chancellor of Waikato University.
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