Andreas Whittam Smith: The candidate who can elicit hope is the winner

In the 1980 presidential election, voters who didn't agree with Reagan still wanted to vote for him

"It's not what you say, it's what people hear." This excellent rule comes from American politics and was first stated by Frank Luntz, a leading Republican practitioner in the art of winning elections. He is a man of ready wit who gave an entertaining interview to this newspaper earlier this month. He said of Jon Huntsman, one of the Republican contenders to take on Barack Obama in the 2012 presidential election, that he was so invisible that "even his own family doesn't recognise him when he comes home".

The Americans have given a lot of attention to political language. No wonder given that presidential campaigns, nothing but words and TV images, are 10 months long. Mr Luntz's insight is part of a wider analysis that elevates emotion above reason. In The Political Brain, for instance, Drew Westen writes that "successful campaigns compete in the marketplace of emotions and not primarily in the marketplace of ideas". George Lakoff, another analyst in the same camp, recounts the story of President Reagan's chief strategist who was puzzled to find that in the 1980 presidential election, voters who didn't agree with Reagan on the issues still wanted to vote for him. Mystified, he studied the matter further. He discovered that what made these people support Reagan was that he talked about values rather than issues.

British politicians have been familiar with this kind of analysis for some time. However, my impression is that David Cameron has learnt the lessons more thoroughly than Ed Miliband. What the three Americans are arguing is that issues are secondary – not irrelevant or unimportant, but secondary. A position on issues should follow from one's values, and the choice of issues and policies should symbolise those values.

I have been checking these rules against Mr Cameron's New Year message and Mr Miliband's important speech given on Tuesday. Mr Miliband indeed began his address with values. Now, it is easy to be critical of other people's use of words, and perhaps I am going to be too hard on the Labour leader. However, Mr Miliband started off by saying that "a lot of people will hear me talk about values" as if this was a new plan rather than values coming from his heart. He went on to say that "the Labour Party stands for fairness and fighting injustice", whereas we want to know what he stands for. Mr Miliband would retort, no doubt, that this is a distinction without a difference, but I am not so sure. Finally, he fell upon a good proposition: "My Labour Party is going to show that we can deliver fairness even when there's less money around."

In contrast, Mr Cameron drew shamelessly on the coming Olympics and Diamond Jubilee, saying that these "magnificent events" gave us an "extraordinary incentive to look outward, look onwards and to look our best: to feel pride in who we are and what – even in these trying times – we can achieve". I cannot resist repeating more of what Mr Cameron said, because, like it or not, it is a very good example of genre. "We honour our Queen as the finest and most famous example of British dedication, British duty, British steadiness, British tradition – let's use these things as a mirror of ourselves, too, a mirror of the nation. Resilient. Realistic. Intelligent. Curious. Enterprising. Inventive. Unswerving." Well, specious maybe, but this does the job.

Mr Westen also wrote about the importance of counterpunching, referring to his beloved Democrats. But he might well have been talking about Mr Miliband's Labour Party. He said that a central psychological principle in shaping voters' thinking is never to let the other side create emotional associations without countering them. That means, among other things, never letting an attack linger without responding to it. "Unfortunately," he added, "Democrats tend to respond to attacks, particularly unfair ones, with a set of strategies that virtually always fail." Either they didn't respond at all, or they responded with a flurry of facts or counterarguments, or they used the "he knows that's not true" or "he's lying" tack. "Why is counterpunching so important?" asks Mr Westen, and answers his own question: "Because failing to counterpunch costs elections."

That is what is happening to Labour in relation to blame for the economic crisis. The party has allowed the Tories unfairly to stick it on them so that Mr Miliband felt compelled in his speech to repudiate his predecessors. He admitted that "the Blair/Brown approach will not be enough" and that "the ideas which won three elections between 1997 and 2005 won't be the ideas which will win the election in 2015. And not just out of necessity, because there's less money around. But because we have to recognise some of the things we didn't achieve." Dutifully honest, but not a winning strategy.

The three writers whose work I have been using argue that eliciting positive emotions such as hope is the best predictor of the success of a candidate. In an age of austerity, it is difficult to do so, but in terms of political language, Mr Cameron comes much closer to pulling it off than Mr Miliband.