Human beings are hard-wired to search for patterns and parallels — especially those that seem to confirm their existing prejudices. Hardly surprising, then, that politicians are so fond of comparisons between elections past and present, and so inclined to pick the precedents that appear to point to their preferred outcomes.

Tories today like to hark back to 1992 when John Major was re-elected on the back of a negative campaign built on questioning Labour’s economic competence and the fitness to govern of its left-leaning leader, Neil Kinnock.

Labour people, meanwhile, are more likely to recall either 1979, when the party was beaten by the Tories despite Margaret Thatcher being less popular than James Callaghan, or 1974, when Harold Wilson managed to snatch back the keys to Downing Street from Ted Heath after just one term — although only after an election in which both the main parties suffered such substantial losses to smaller, insurgent outfits that neither could muster an overall majority.

Clearly, both narratives, have something going for them. But they may be missing the most obvious parallel of all — one that should give Ed Miliband rather more cause for hope than David Cameron.

It is 1970. The government has gone to the country with two obvious aces up its sleeve. The economy finally seems to be back on track, and the prime minister is clearly seen as up to the job of running the country — unlike the leader of the opposition, who, despite five years in the job, regularly flops in the Commons and just can’t seem to connect with the electorate.

As the campaign wears on, however, things don’t go quite the way the government has planned. For one thing, economic growth doesn’t seem to be delivering the anticipated “feelgood factor — almost certainly because real wages haven’t been rising fast enough or long enough. For another, while the leader of the opposition can hardly be said to have turned the public’s impression of him on its head, he is nonetheless proving a better communicator and campaigner than many imagined — including those in his own party who have previously despaired at his dogged insistence that, ultimately, substance will win out over style.

Sure enough, when the votes are finally counted, an election that should have been safely in the bag for the government turns out to be a victory for the opposition — and a personal triumph for the man leading it.

Clearly, the parallel isn’t perfect for Mr Miliband. After all, Ted Heath, the winner in 1970, was a Tory rather than a Labour leader. Even more awkwardly, his government turned out to be an unmitigated disaster, resulting in two general election defeats on the trot and his replacement by a world-famous successor.

The parallel is nevertheless a striking one when it comes to the campaign itself. Unless the polls — and, indeed, the body language and mood music — are profoundly misleading, Mr Miliband is, to the surprise of some of his friends as well as his foes, having a better time of it than most of his opponents, not least Mr Cameron. Thursday’s challengers’ debate was another pretty good night for the Labour leader.

True, Miliband, although he’s judged almost as “likeable” as Cameron, still lags some way behind him on “best prime minister”, as well as on attributes like “being good in a crisis” or “having a clear vision for the country”. But public satisfaction with the way he is doing his job, while still negative, has improved much more during the campaign than the Conservatives (and many commentators) were expecting. And, he appears, if anything, to be widening his lead over the PM on being “in touch with ordinary people” and looking after all sections of society.

This is not to be sniffed at. Elections are more than an extended executive search process. They are also about representation. Moreover, research suggests that voters judge challengers slightly differently from incumbents. It helps, of course, if, to coin a phrase, they’ve “got it”. But it’s just as important that they “get it”, too.

Cameron still has the edge on the former. However, it may not be big enough to render Miliband’s lead on the latter irrelevant. Yes, this is 2015 and not 1970. But if the PM is not careful, Ed could very well do a Ted.