Is Boris Johnson actually leading the UK back to the centre?

It looks like the adults are at last starting to take over the playroom. I am referring to the increasing probability that Joe Biden will become the Democratic Party's choice to challenge Donald Trump for the presidency of the United States; and the near certainty that Sir Keir Starmer will be declared next month as the new Leader of the Labour Party and hence the primary challenger to Boris Johnson for the British premiership.

What is also happening in Britain, though perhaps not quite so much in America, is a swing back towards the centre-ground. Both major British parties have realised that elections are not won from the left or the right. It is a truth the Democratic party also needed to rediscover. This convergence towards the centre, which is characteristic of the politics of both Johnson and Starmer, indicates that the tide has gone out on radical utopian solutions, whether a libertarian free-market paradise or a state-controlled socialist one. The British have never liked ideologies, which is why they, unlike some we could mention, have never seriously flirted with Communism or Fascism.

However it would not be easy to label the power behind Boris Johnson's throne, Dominic Cummings, as a followers of either of those Nirvana-mongers. He is more an anarchist, someone who believes in the therapeutic properties of chaos. Hence all social institutions need a wrecking ball because they stand in the way of progress, even though anarchists cannot actually define what progress looks like. Nevertheless he is still an ideologue, and sooner or later he will have become Boris Johnson's greatest liability. When he has finished with the judiciary, the civil service and the BBC, and he turns on the Church of England, the universities and the monarchy, the public will have had enough.

But Johnson is only interested in one thing: holding onto power. If Cummings became a threat to that, he will be dropped. At the moment he serves a useful purpose as a scourge of the Westminster and Whitehall elites, which he calls "the blob", who are blamed for inflicting the European Union on a reluctant population and for defending it against Brexit after the 2016 referendum.

Johnson's focus, as he repeats again and again, is on the traditional Labour voters in Midlands and Northern constituencies who, as he puts it, "lent" him their votes in December 2019 but might easily take them back again – especially once Brexit is a done deal. And as a biographer of Winston Churchill he knows that gratitude is not a powerful force in politics. Churchill thought he was bound to win the 1945 election, having just won the Second World War. But voters tend to look forward, not back. Donald Trump needs to remember that too.

To hold on to those "lent" votes in those underprivileged communities, Johnson is forced to adopt what might look like a more naturally Labour programme of government-sponsored reform and development. Not having any ideological commitment to free market economics, he is prepared to use the power and influence of the State to "level up" living standards – to bring people in Workington, Cumbria, closer to people in Warlingham, Surrey. Whether that can be done without inflicting pain on the people of Warlingham, through tax rises and other redistributive measures, remains very doubtful. But what this strategy requires is for Johnson to plant his policy tanks on Starmer's lawn; or to change metaphor, to steal his clothes.

He is not stealing those clothes because he has been converted to a firm belief in social justice, but because this is the way to hold on to power. But that is typically Tory. Conservatives do not have a political philosophy beyond the conviction that "people like us" ought to be in charge. And that means we are seeing a convergence on to the centre from the right, which matches Labour's convergence on the centre from the left.

And again, gaining and holding on to power has become Labour's political imperative too. Not least through watching the example of Boris Johnson, and surreptitiously listening to Tony Blair, like members of the French Resistance hiding under the bed clothes while tuning into the BBC. It has overtaken purity of political ideas as the dominant factor.

Just as American Democrats are opting for normality and electability with Biden in preference to Bernie Sanders's offer of a Promised Land, so Labour Party members see Starmer's greatest asset as his sense of political gravitas, or "bottom", and therefore of being a grown-up. His two rivals at the moment, Rebecca Long-Bailey and Lisa Nandy, would make a good showing at a sixth-form (or in the US, High School senior) debating society. But they need to go through the tumble-dryer of life a few more times before they are ready for high office.

And like Sanders, Jeremy Corbyn's formula for healing the ills of the nation looks a lot too good to be true. People quickly see through door-step sellers who overstate the brilliance of their product. The offer of "jam today" or even "jam tomorrow" doesn't work. Grown-up people know that jam is never free.