The problem with Donald Trump is not that he is crazy, but that he is crass

In Alan Bennett’s play The Madness of George III, a political crisis strikes Great Britain when the monarch loses his marbles. You may recall Nigel Hawthorne’s riveting performance in the role of King George in the film version, at first indefatigable, if irascible, in performing his royal duties, then suddenly struck down by wild, raving lunacy.

These days, it is in America that the question is asked with increasing frequency: is the head of state off his head? In a new book, The Dangerous Case of Donald Trump, 27 psychiatrists and other mental health experts – including Judith Lewis Herman of Harvard Medical School and Bandy Lee of the Yale School of Medicine – warn that “anyone as mentally unstable as Mr Trump simply should not be entrusted with the life-and-death powers of the presidency”.

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The madness of King Donald is not news in Washington. But, until last week, the story in Britain was Trump’s badness, not his madness. Then, on Tuesday and Wednesday, the president retweeted three posts from the deputy leader of the fascist splinter group Britain First, each featuring a video purporting to depict Islamic violence.

When Theresa May expressed her disapproval, Trump shot back: “Don’t focus on me, focus on the destructive Radical Islamic Terrorism that is taking place within the United Kingdom.”

Not having read The Dangerous Case of Donald Trump, the British political class reacted in the old-fashioned way. In the Commons, opposition MPs lined up to denounce Trump as a “fascist”, “stupid” and “racist, incompetent or unthinking”.

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Do keep up. The president is mad, not bad. Just the other day, he was telling people that the infamous Access Hollywood tape is fake. Two weekends ago, he was fantasising that he had turned down Time magazine’s proposal to make him – for the second year running – Person of the Year.

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The counterargument to all this comes from my good friend Bret Stephens. Far from being mad, he argues, Trump is cunningly exploiting the power of social media to drive his political opponents into their own form of madness, to distract everyone else’s attention from all that is going wrong on his watch.

I have a different view. Like Bret, I don’t think Trump is nuts. He’s just crass and always has been. Unlike Bret, however, I don’t think Trump is failing. He is on the verge of a major legislative breakthrough: a package of tax cuts that are as popular on Wall Street as they are hated by Democratic economists.

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Yes, I know. Fewer than 40 per cent of Americans approve of the president. But the US economy is growing at about 3.5 per cent. The stock market is at record highs. And, although I have my doubts about adding to the deficit, respectable economists insist the Republican tax bill will benefit not just the rich but also working- and middle-class families by boosting investment and growth – and that the Trump administration’s push to reduce burdensome regulation will have even more positive effects.

The problem is that, in his incorrigible crassness, Trump drowns out the signal of meaningful policy achievement with inconsequential noise.

In this, unfortunately, he is not abnormal in the least. On the contrary, he is the incarnation of the spirit of our age. His tweets – hasty, crude and error-strewn – are just one symptom of a more general decline in civility that social media have encouraged. According to researchers at New York University, a tweet is 20 per cent more likely to be retweeted for every moral-emotional word (such as “hate”) that it uses.

One of many problems with the decline of civility is that uncivil discourse is so difficult for civil people to take seriously. As a result, serious issues become trivialised and civil people assume, wrongly, that it is Trump we should really worry about.

Mahatma Gandhi is said to have been asked once what he thought of Western civilisation. He replied, wittily, that it would be good idea. In these days of Western uncivilisation, I find myself in agreement. The problem is not the madness of King Donald, nor even his badness. By George, it’s his infernal rudeness.

Niall Ferguson’s new book is The Square and the Tower: Networks, Hierarchies and the Struggle for Global Power