IF THE history of the world is but the biography of great men, as Thomas Carlyle put it, the history of Britain since the 1960s is but the biography of two great men and one woman. As Labour home secretary from 1965-67, Roy Jenkins took the government out of the bedroom with a series of liberalising laws on divorce, homosexuality and censorship. As Tory prime minister from 1979-90 Margaret Thatcher unleashed the power of markets. The main job of their successors was to come to terms with these twin revolutions: Tony Blair converted Labour to Thatcherism and David Cameron converted the Tories to Jenkinsism.

Before Brexit it looked as if that was it: the party that could produce the best synthesis of Thatcher and Jenkins would win. But today a third figure hovers over British politics: a man who was born in 1912—eight years before Jenkins and 13 before Thatcher—but whose influence seems to grow by the day. One of Enoch Powell’s most famous observations was that “all political lives, unless they are cut off in midstream at some happy juncture, end in failure.” His political life is enjoying a posthumous success.

Powell put two issues at the heart of his politics: migration and Europe. He convulsed the country in 1968 when he declared in a speech in his native Birmingham that mass immigration would produce social breakdown—that “like the Roman, I seem to see the River Tiber foaming with much blood.” And he campaigned tirelessly against the European Economic Community. These two passions were united by his belief in the nation state. He thought that nations were the building blocks of society and that attempts to subvert them, through supranational engineering or global flows of people, would end in disaster.

Powell didn’t have the same direct influence as Thatcher or Jenkins. Thatcher was prime minister for 11 tumultuous years. Jenkins lived his life at the centre of the establishment. Powell spent only 15 months of his 37-year political career in office, as minister for health; nothing of substance bears his name on the statute books. In his new book, “The Road to Somewhere”, David Goodhart, a liberal critic of multiculturalism who has been accused of “liberal Powellism”, thinks that his “rivers of blood” speech was doubly counter-productive: it toxified the discussion of immigration for a generation and set the bar to successful immigration too low (no rivers foaming with blood, no problem).

Yet Brexit is soaked in the blood of Powellism. Some of the leading Brexiteers acknowledge their debt to Powell: Nigel Farage regards him as a political hero and says that the country would be better today if his words had been heeded. Powell lit the fire of Euroscepticism in 1970 and kept it burning, often alone, for decade upon decade. He provided the Eurosceptics with their favourite arguments: that Europe was a mortal threat to British sovereignty; that Britain’s future lay in going it alone, “her face towards the oceans and the continents of the world”; that the establishment had betrayed the British people into joining Europe, by selling a political project as an economic one, and would betray them again. History has also been on his side. David Shiels, of Wolfson College, Cambridge, points out that, in Powell’s time, the questions of immigration and Europe were distinct (the immigration that worried him was from the Commonwealth). Europe’s commitment to the free movement of people drove the two things together and gave Powellism its renewed power.

Just as important as his arguments was his style. Powell was the first of the new generation of populists cropping up across the West, a worshipper of Nietzsche in his youth, a professor of classics by the age of 25 who nevertheless considered himself a true voice of the people. He believed that the British establishment had become fatally out of touch on the biggest questions facing the country and used his formidable charisma—insistent voice tinged with Brummie, hypnotic stare—to seduce his audiences.

Powell’s errors were legion. He regarded British nationhood as a fixed entity rather than something that was constantly being reinvented. He underestimated the country’s ability to absorb foreigners. Some prominent Brexiteers, such as Priti Patel, who is now a cabinet minister, were the children of immigrants, and the most recent Tory to hold Powell’s old seat, Wolverhampton South West, was a Sikh, Paul Uppal. He combined a high-flown love of his own nation with a chilly indifference to other people’s nations. He didn’t pay enough attention to the fact that nationalism can easily turn rancid: on March 31st a 17-year-old asylum-seeker was beaten almost to death in London by a gang of youths. Nor did he recognise that it can easily become ridiculous: on April 2nd a former leader of the Conservative Party, Michael Howard, talked about going to war with Spain over Gibraltar.

Filled with foreboding

But he did recognise one big thing: that the prophets of globalisation and European integration erred badly if they thought that national loyalties would either melt away or become so anodyne that they didn’t matter. Britain’s political parties now need to come to terms with the Powell question of national identity in much the same way that they once had to come to terms with the Jenkins question (social liberalism) and the Thatcher question (economic liberalism). Those who fail to make the adjustment will be doomed to marginalisation. So far the Tories have taken to this more easily than Labour. Whereas Theresa May’s Toryism is rooted in provincial England, Labour’s two core constituencies—liberal intellectuals and manual workers—are at war with each other on national identity.

The established parties need to deal with this problem not just because their success depends upon it but also because, if left to fester, untamed nationalism can be a powerfully destructive force. Powell was restrained by the power of the old British establishment and by his reverence for Parliament. Today’s pound-shop Powellites don’t suffer from any such restraints.

Economist.com/blogs/bagehot