Sitting on the sun-dappled terrace of the House of Lords, watching the Thames flow, Lord Nigel Lawson explains that the June 23 referendum, which he hopes will withdraw Britain from the European Union, was never supposed to happen. It is, he says, the fulfillment of a promise Prime Minister David Cameron expected to be prevented from keeping.

Going into the 2014 general election, Cameron, heading a coalition government with Liberal Democrats, placated anti-EU Conservatives by promising a referendum on the EU membership. He expected that another close election would leave him again heading a coalition, and that he would be able to say, truthfully, that his pro-EU Liberal Democrat partners would block a referendum. But his Conservative Party won a large parliamentary majority, inconveniently liberating Cameron from the constraints of a coalition and leaving him with an awkward promise to keep.

Full of years, 84 of them, and fight, Lawson has spent 42 years on the Thames embankment, as a member of both houses. He is impatient with the proposition that it is progress to transfer to supra-national institutions decision-making that belongs in Britain’s Parliament.

When Britain votes on whether to withdraw from the EU, it will be deciding for or against the constraints of deepening involvement with a political entity born from cultural despair about Europe’s past and complacency about a European future of diminishing social dynamism and political democracy. Britain will consciously choose between alternative national destinies that Americans are less consciously choosing between by their smaller choices that cumulatively subordinate them to a vast, opaque and unaccountable administrative state.

Cameron says leaving the EU is unnecessary because Britain has rejected membership in the eurozone currency and is not bound by the EU’s open borders policy. Advocates of “Brexit” reply that if the common currency and open borders, both crucial attributes of the EU, are defects, why remain?

Cameron says leaving the EU would be imprudent for security reasons. Wielding the fallacy of the false alternative, he says those who favor leaving the EU favor “going it alone” and “isolationism.” They respond that Britain out of the EU would remain Europe’s foremost military power. When Cameron recalls “war in the Balkans and genocide on our continent in Srebrenica,” Leave advocates note that the EU had nothing to do with suppressing this, which fell to NATO and especially the United States, neither of which would be diminished by Britain leaving the EU.

Cameron invokes “the serried rows of white headstones” on British graves in military cemeteries on the continent as a “silent testament to the price that this country has paid to help restore peace and order in Europe.” Historian Andrew Roberts tartly responds that the British war dead “fought for British independence and sovereignty, not for European unification.”

The Remain camp correctly says that Britain is richer and more rationally governed than when European unification began. The Leave camp, however, correctly responds that this is largely in spite of the EU — it is because of decisions made by British governments, particularly Margaret Thatcher’s, in what is becoming a shrinking sphere of national autonomy.

In 1988, Thatcher said: “We have not successfully rolled back the frontiers of the state in Britain, only to see them reimposed at a European level with a European super-state exercising a new dominance from Brussels.” Stressing Britain’s European credentials, she also said “our maps still trace the straight lines of the roads the Roman built.” But today’s Leavers, who carry the torch of Thatcherism, do not favor straight lines drawn by foreigners. They prefer G.K. Chesterton’s celebration of spontaneous, unplanned cultural particularities:

Before the Romans came to Rye or out to Severn strode,

The rolling English drunkard made the rolling English road.

In politics, sensibility is prior to and inseparable from philosophy. The referendum will record, among other things, the strength of the revulsion many people here feel about a multiculturalism that celebrates every permutation of identity — except that of nationality. This is a trans-Atlantic revulsion.

What Daniel Patrick Moynihan, an Irish-American and Anglophile, called “the liberal expectancy” is the belief that the rise of reason and science would mean the waning of pre-modern forces such as religion, ethnicity and even nationality, which would be regarded as an anachronistic tribalism. British voters, who may be as weary as many Americans are of constantly being told that they cannot “turn back the clock,” and that history’s centralizing ratchet has clicked irreversibly too many times, might soon say otherwise.

© 2016, Washington Post Writers Group