With then-British Prime Minister Theresa May in the foreground, Boris Johnson, left, greets President Trump at a working dinner meeting at NATO headquarters in Brussels on May 25, 2017. (Matt Dunham/Reuters)

Michael Dobbs is a former foreign correspondent for The Post and author of “The Cold War" trilogy.

As an expatriate Brit who moved to the United States more than two decades ago, I have been following the Brexit drama with fascination and horror. But what I did not fully appreciate before returning to the United Kingdom is how closely British politics track American politics — and vice versa.

My visit coincided with the final stages of the Conservative Party leadership contest and the anointing of Boris Johnson as Britain’s new prime minister. Reflecting the dysfunctional state of British politics, Johnson was elected on the basis of fewer than 100,000 votes, from aging, largely male, overwhelmingly white Conservative Party members who are completely unrepresentative of the overall population. His public approval ratings are even more dismal than those of President Trump. According to a YouGov poll, only 28 percent of Britons welcomed his election and 47 percent were “dismayed” or “disappointed,” while the remainder were too apathetic to express an opinion.

At first sight, it would appear that the “Britain Trump” — the American Trump’s accolade — is tied down on every side. The European Union has already rejected his demand for rewriting the withdrawal agreement that was painstakingly negotiated by his immediate predecessor, Theresa May. If he attempts to engineer a no-deal exit from the E.U., he will face a rebellion from the pro-Europe wing of his own party. Given his tiny parliamentary majority, it would take only a few defections to bring him down.

There is, however, a way out of the political straitjacket — modeled on the tactics employed by his American counterpart. All signs now point to an early general election that Johnson has a good chance of convincingly winning, given the peculiarities of the British electoral system. Taking a leaf out of the Trump playbook, Johnson is setting himself up to run on a “Make Britain Great Again” chauvinist platform. While the idea of a no-deal Brexit horrifies many Britons, including big business and trade unions, Johnson evidently believes he can win an election by mobilizing his base and keeping his political opponents divided.

He may well be right. The fact is that a British prime minister does not need a popular mandate to obtain the keys to 10 Downing Street. He can secure a comfortable parliamentary majority with 35 percent of the vote — as Tony Blair did in 2005 — or even less.

From an American perspective, it is helpful to think of the House of Commons as an electoral college on steroids. The popular vote is irrelevant. What matters are 650 individual, first-past-the-post races for individual constituencies. An unpopular minority party can emerge as a big winner as long as it piles up votes in the right places. A strong brand and clever political positioning are all-important.

By moving rightward and co-opting the hard-line Brexiteers, Johnson is calculating that he can consolidate most of the “leave” vote behind him. The “remain” vote, meanwhile, is split between Labour, the Liberal Democrats, the Greens, the Scottish nationalists and various “independent” groups. Underpinning the Johnson strategy is the need to avoid the scenario of the recent Peterborough by-election, in which Nigel Farage’s new Brexit Party siphoned away much of the Conservative vote, allowing Labour to win the seat.

A strong clue to Johnson’s intentions is his recruitment of the mastermind of the 2016 leave campaign, Dominic Cummings, as his senior adviser. Articulate and disheveled, Cummings combines the anti-establishment fervor of a Stephen K. Bannon with the political ruthlessness of a Lee Atwater. As in 2016, when he fanned fears of uncontrolled immigration into Britain from Eastern Europe, his job will be to come up with the winning political message, regardless of the actual facts.

An electoral coup of the type now being contemplated by Johnson and his advisers would be much more difficult to accomplish in most European countries. A German-style system of proportional representation obliges the political party that wins most votes in an election to share power with others. The French system of two rounds of voting in presidential elections also favors the political center at the expense of the extremes. In both cases, a leader needs to command an electoral majority in order to govern. In Britain and the United States, this is not the case.

Traditionally, we Anglo-Saxons have prided ourselves on our political moderation and pragmatism. Our electoral systems have provided for stable, strong and sensible governments over many decades, based on widely shared values and national goals. But now, it seems, these same systems reward crude populism. Perhaps the time has come to rethink political arrangements that favor a determined minority over a diverse majority.

Read more:

Maya Goodfellow: Boris Johnson and his regressive cabinet mean disaster for Britain

Anne Applebaum: Boris Johnson’s victory proves it’s fiction, not fact, that Tories want to hear

The Post’s View: Boris Johnson is optimistic. How long will that last?

Fareed Zakaria: Boris Johnson will accelerate the decline of Europe

Ryan Bourne: Don’t lump Boris Johnson together with Donald Trump