It's no surprise that Boris Johnson is Donald Trump's biggest fan – they seem to be locked together in some kind of monstrous infinity loop

In this brief hiatus between the two halves of Donald Trump’s whirlwind diplomatic tour, midway between the post-G7 summit tweet offensive and his speed dating encounter with Kim Jong-un (60 seconds to decide whether to bed him or shed him) in Singapore, a question begs itself.

It isn’t a new one. As with most of the major Trump conundra, it’s been in the air for the two years since a gaping world had to confront the real possibility of his presidency.

But the question of whether the craziness has become normalised feels more oppressive than ever.

The answer is in constant flux. The last article I read last night, on the Daily Beast, cogently argued that it has: that examples of the previously unthinkable have erupted so frequently that, it being all organic life form’s survivalist way to adapt to even dramatically altered conditions, we are largely habituated to the lunacy already.

The first article I read early this morning, meanwhile, concerned Trump’s tweetblast at Justin Trudeau for being “dishonest and weak”, and a jolt of electrifying surreality surged through the mind again.

That came as a relief. It will be a dreadful day when the vision of a president bulldozing the existing world order – ostentatiously favouring a hostile power such as Russia over America’s closest allies – musters no more than a nonchalant shrug.

Yet the signs that the once-unthinkable is becoming the norm cannot be ignored. Thanks in part to the familiar process of transatlantic osmosis, we can glimpse it here in the bulbous shape of our own Baby Trump – a phrase that may strike you as a tautologous, but which refers in this context to Boris Johnson.

These two overgrown toddlers seem symbiotically linked.

When Johnson was appointed to disbelief in July 2016, at just the moment a Trump victory was becoming credible, the notion of a foreign secretary performing as he has and keeping the job beggared belief.

Any previous incumbent who falsely smeared a British national imprisoned in Iran, and then projected blithe unconcern about it, would have been yanked out of office within days. No predecessor could have ridiculed his prime minister once, as he has multiple times, and survived.

Obviously, the fragile cabinet balance over Brexit is central to his indestructibility. But there is a little more to it than that. The threshold for what qualifies as acceptable has been so lowered by Trump that a recording of a foreign secretary savaging his own government’s negotiation tactics, while praising the alleged method in Trump’s diplomatic madness, feels unnervingly close to mundane.

While there is no evidence that Boris leaked the tape, it would make sense if he did. He will appreciate the nascent but discernible shift in US opinion, where a booming economy is hiking Trump’s popularity ratings.

They could plummet again for any number of reasons, and they are still historically low. But so are US unemployment figures, and if they remain so during another two years of economic growth, there is a strong chance of Trump surfing the normalisation wave to a second term.

That prospect may strike Johnson as vindication for his Trump-with-a-Classics-degree persona. Trends always cross the Atlantic in an easterly direction, and faster than ever in the internet age. If the American electorate is becoming inured to the embarrassment of being led by someone whose capacity for being entertainingly cretinous is surpassed only by his unwillingness to master a brief, the British might follow suit.

If enough moderate Tory MPs sense this, and reckon that Trump will be in the White House until early 2025, they might reluctantly see a working relationship as the most essential counterweight to post-Brexit economic distress. In that event, they might swallow their reservations and put Boris among the final two candidates for whom an adoring party membership will pick the next leader.

A feature of recent history is how often presidents and PMs have been mirror images. The free-marketeering swagger of Thatcher and Reagan, the studied dullness of Major and the elder Bush, the faux-empathetic lawyerly cynicism of Clinton and Blair... why not the double-down-on-the-lies, infantile narcissism of Trump and Johnson?

If Johnson’s thinking runs on those lines, there may be a method in his Trump-lauding madness.

The smart punter will still probably give him a wide berth and lump on Sajid Javid instead. Perfectly positioned for one of those late bursts from the pack that tend to decide the Tory leadership stakes, Javid looks likeliest to benefit if May loses her precarious balance on the Brexit tightrope within the next few months.

Yet Trump and Johnson have seemed locked together in some kind of monstrous infinity loop, the one powering the other, for two years. If you believe that: a) Brexit wouldn’t have happened but for Johnson’s last minute decision to spearhead Leave, as seems likely; and b) that Brexit turbo-charged the anti-establishment, isolationist sentiment that narrowly handed Trump an incredibly close election, as many do, then it follows that without Johnson, there would be no President Trump.

If Trump’s subsequent efforts to normalise the blood-chillingly abnormal were to return the favour, by de-fanging the notion of Johnson in Downing Street of its venomous incredibility, then one thing you couldn’t deny, as you bought the one-way ticket to anywhere and raced to the nearest airport, is the hideous beauty of the symmetry.