There have been so many dizzying gyrations in politics that it is easy to lose all sense of orientation. Episodes from the recent past already feel remote, given the way ground has shifted beneath our feet, as if they took place in some distant realm. Cleggmania, for instance. Yes, it really did come to pass in 2010 that a Liberal Democrat leader wowed the audience in a televised election debate. Yes, that party did then soar in opinion polls. The effect was not sustained, but it was potent enough to eclipse the fresh-faced shine that David Cameron had hoped to radiate through the campaign. It propelled Nick Clegg into government.

That was only seven years ago. UK membership of the European Union was not seriously up for negotiation, and Jeremy Corbyn was not seriously Labour’s candidate to be prime minister. But it was the same country and, give or take a few deaths and comings of age at the margins, it had the same electorate. How did so many people change their minds about so much?

One explanation, popular among those who are enthusiastic about the changes – the Corbynites and more fervent Brexiteers – is that the centre ground of politics has collapsed. In this analysis, voters grew disillusioned with a cosy elite of liberals and technocrats, all alike in accent and education, representing an ideological consensus that eliminated meaningful distinctions between Labour and Conservative.

The dramatic shift in politics is thus explained by an appetite for radical alternatives to a discredited establishment. Some of that must be true. Since 2010, there have been too many electoral upsets for anyone to reasonably infer affection for the way things had been chugging along. But it doesn’t automatically follow that a vote for change represents a vast increase in the available market for political radicalism. Or, put another way, we can infer that people want change, but not necessarily that they want massive, drastic, irreversible, epoch-defining change. It is quite possible that many of them want just a bit of change. They want a breath of fresh air, as opposed to wanting all the windows broken and a political gale to blow everything inside out.

May and Cameron are different characters from the same Tory central casting agency

That interpretation would be consistent with the electoral shifts that appear to show a cratering of the centre. If it is true, for instance, that the EU referendum result described a national cry of rage against The System, it is presumably also the case that the social and economic conditions for that pang were in place well ahead of June 2016. Yet just a year earlier, Britain reappointed its incumbent prime minister, an old Etonian stockbroker’s son with impeccable establishment credentials. In five weeks’ time the same country looks certain to award an enhanced majority to an Oxford graduate and clergyman’s daughter who served for six years as home secretary in the old Etonian’s cabinet. May and Cameron are different characters from the same Tory central casting agency.

Much commentary since the EU referendum has focused on the volume of Brexit support in areas that traditionally vote Labour. In the left analysis, those former heartlands suffered decades of political drought, parched through lack of economic and cultural irrigation, and are now ready to catch light in a radical inferno. That a wave of working-class anger appears to have been channelled into support for a project developed and advocated by Tories and Ukip is explained by the long absence of an authentic socialist alternative. In short, it is all apparently Tony Blair’s fault.

The frustration in Brexit-backing Labour seats is undeniable, and it surely has deep historical roots, but it still doesn’t follow that revolution is in the air. The great success of the leave campaign was to reassure people that quitting the EU was the less disruptive option – that it represented a restoration of order, while continuing membership signified endless change to the character and complexion of the country. And the corollary of that victory was the remain side’s failure to convince enough people that Brexit really was the wild and radical option: a leap into the dark, a gamble with the nation’s prosperity and security. The UK is not leaving the EU because a majority of voters fancied a reckless flutter, but because only a minority thought the danger was real.

Millions of people, leavers and remainers, will vote for May next month because they perceive her to be the exact opposite of radical. They see in her the reassuring face of cautious, managed change. She is their emblem of continuity, attachment to the way things have always been done, and the avoidance of unnecessary risk.

That judgment is surely misplaced, and it is encouraged by the prime minister’s controlled style more than by the substance of her actions. But Labour can’t expose the false promise of May’s reasonable moderation by clinging to the belief that moderation itself is corrupt and despicable, nor by telling itself that the thing British voters really crave in their governments is a wild-eyed flight from caution.

One of the insights that helped New Labour to its first landslide victory was that change and continuity do not have to be mutually exclusive. A successful campaign contains promises of both. Excitement about things being very different should not be mistaken for a revolutionary demand that nothing stay the same. Blair understood what that meant in 1997: the balance between public impatience to see a sleazy and heartless Tory administration swept away, and residual wariness of what a Labour government might do to a buoyant market economy.

Of course that no longer works as an account of the political centre ground 20 years on. Facts change, the world turns, opportunities are missed, fresh faces turn haggard through incumbency.

Goodwill is spent. The prospect of a comeback for 90s vintage Blairism is no likelier than a sudden revival of Cleggmania. But the absence of charismatic candidates, uncontaminated by office, who might lead a reasonable, moderate “centre-ground” alternative to May’s government does not prove that victory is no longer found in the centre. The virtues of compromise and pragmatism have not lost their intrinsic value.

The Tories aren’t winning because Britain has finally learned to love radicalism. They are winning because enough people believe that their radical leader is a moderate.