Donald Trump will be the Republican candidate for president. He might even become president of the US. It is hard to exaggerate the significance and danger of this development. The US was the bastion of democracy and freedom in the 20th century. If it elected Mr Trump, a man with fascistic attitudes to people and power, the world would be transformed.

Mr Trump is a misogynist, a racist and a xenophobe. He glories in his own ignorance and inconsistency. Truth is whatever he finds convenient. His policy ideas are ludicrous, where they are not horrifying. Yet his attitudes and ideas are less disturbing than his character: he is a narcissist, bully and spreader of conspiracy theories. It is frightening to consider how such a man would use the powers at the disposal of the president.

Andrew Sullivan, the conservative commentator, recently wrote: "In terms of our liberal democracy and constitutional order, Trump is an extinction-level event." He is right.

It might prove surprisingly easy for President Trump to find people willing to execute tyrannical orders or to compel the unwilling to do so. By exaggerating crises or creating them, a would-be despot can pervert judicial and political systems. The presidents of Russia and Turkey are skilful exemplars. The US has an entrenched constitutional order. But even this might buckle, particularly if the president enjoyed impeachment-proof support in Congress.

Plato

Mr Sullivan calls on Plato, the greatest of anti-democratic philosophers, in aid. Plato, he reminds us, believed that the more equal a society became the less it would accept authority. In its place would come the demagogue who offers simple remedies for complex problems.

Mr Trump is the pied piper of the enraged and the resentful. He has risen, argues Mr Sullivan, as the man who will “take on the increasingly despised elites”. Moreover, the media revolution has facilitated this rise by erasing “almost any elite moderation or control of our democratic discourse”.

Demagoguery is an Achilles heel of democracy. Yet the Athenian democracy, in which Plato lived, did not give way to a domestic tyranny but was born from one. It was the Macedonian king who ended it in 338BC.

Above all, Mr Sullivan understates the role of elites. In the case of the US, he argues that wealth is unable to buy the presidency. Mr Obama defeated Mr Romney, for example. But money buys influence at lower levels of politics. More important, elites shape the economy and society. If a swath of the people is enraged, elites bear responsibility.

The righteous attachment of the Democrats to the rights of women and, still more, the cause of minorities, defined by race, sexual orientation and identity, transferred the allegiance of the white, male middle classes, particularly in the old South, to the Republicans. The racial element in “Obama derangement syndrome” is quite clear.

Then Republicans treated these supporters to a “bait and switch”. They needed these votes for what their donors most desired: low taxes, weak regulation, free trade and liberal immigration. To make these causes goals of the Republican party, elites had to turn the government into the enemy. They also had to entice culturally conservative supporters with promises of change that were never likely to be met.

Bailouts

In addition, elites on both sides promoted economic changes that ended up destroying trust in their competence and probity. In this, the financial crisis and consequent bailouts were decisive.

Yet by then the middle classes had suffered decades of real income stagnation and relative income decline. Globalisation has brought huge benefits to many of the world’s poor. But there were significant domestic losers. Today, the latter believe that those who run the economy and polity impoverish, exploit and despise them.

Even Republican elites have become their enemy and Mr Trump has become their saviour. It is no surprise that he is a billionaire. Caesar, aristocratic leader of the popular party, brought forth “Caesarism”, the rule of the charismatic strongman that Mr Trump wants to be.

A healthy republic does not require equality, far from it. But it does require a degree of mutual sympathy. Sudden wealth from new activities – conquest in ancient Rome, banking in medieval Florence – can corrode social bonds. If civic virtue vanishes, a republic becomes ripe for destruction.

Economic, social and political changes have brought the US to the point at which a significant part of the population seeks a strongman. It must be sobering to Republican elites that their base chose Mr Trump over Ted Cruz and Mr Cruz over everybody else. The party elite played populist games, notably in their adamant refusal to co-operate with the president. Those better at such games have defeated them.

Conservatives

Mr Trump realises that his supporters have no interest in the limited state beloved of conservatives. Their desire is rather the restoration of lost economic, racial and sexual status. His response is to promise massive tax cuts, sustained spending and reduced debt. But he does not need logical consistency. That is for the despised “lamestream media”.

Hillary Clinton is a weak candidate, tainted by her husband's failings and her position in the establishment, and short on political talent. She ought to win but might not. But even if she were to win, that would not end this story.

Mr Trump has called forth new political possibilities. But it is not mainly an excess of democracy that has brought the US to this pass. It is far more the failings of short-sighted elites. Some of what has happened was right and so should not have been avoided. But much of it could have been. Elites, particularly Republican elites, stoked this fire. It will be hard to put out the blaze.

– Copyright The Financial Times Limited 2016