Clodagh Kilcoyne / Reuters

American commentators have spent the weekend pondering the similarities between Britain’s vote to leave the European Union and America’s impending vote on whether to take leave it of its senses by electing Donald Trump. The similarities have been well-rehearsed: The supporters of Brexit—like the supporters of Trump--are older, non-college educated, non-urban, distrustful of elites, xenophobic, and nostalgic. Moreover, many British commentators discounted polls showing that Brexit might win just as many American commentators, myself very much included, discounted polls showing that Trump might win the Republican nomination. Brexit may even result in the installation this fall of a new British prime minister, Boris Johnson, who is entertaining, self-promoting, vaguely racist, doughy, and orange. It’s all too familiar.

But there are two crucial differences, which should offer Americans hope. The first is that Brexit is an idea whereas Trump is an actual person. For many in Britain, leaving the European Union became a way of expressing their frustration with immigration, erosion of sovereignty, economic stagnation, and unaccountable elites. Many Americans feel a similar frustration and if given the chance to signal it via referendum—Should America pull out of NAFTA? Should America’s allies shoulder the entire cost of US troop deployments? Should America break up large investment banks?—a majority of Americans might vote yes.

But in presidential elections, where Americans choose not only a head of government but a head of state—the personification of national identity—how voters feel about the personality of the candidates matter a lot. Thus, voters cannot merely shake a fist at the American establishment. They must actually vote for Donald Trump.

Were Trump a highly gifted politician, perhaps he could forge an anti-establishment majority that brought cultural conservatives angry about immigration and political correctness together with Bernie Sanders supporters angry about Wall Street and trade. But he’s not. In the last few weeks alone, his racist attack on Judge Gonzalo Curiel and his conspiratorial, narcissistic response to the Orlando shooting have pushed his unfavorability rating back over 60 percent.

Trump’s response to Brexit underscored the reasons. Instead of discussing its impact on the United States, he discussed its impact on his wallet. “Whenever the pound goes down,” he declared, “more people are coming to Turnberry,” his Scottish golf course. Asked if he had discussed Brexit—one of the most important geopolitical events in Europe since World War II—with his foreign policy advisors, he said “there’s nothing to talk about.” This kind of ignorance and selfishness alienates even some Americans who are strongly anti-establishment. A sizable group of voters wants to upend Washington but can’t stomach doing so through him.

The second reason to doubt that Brexit is prologue for Trump is the role of nationalism. The campaign to leave the EU successfully tapped into a fear that Britain was ceding its identity to foreigners, both the bureaucrats in Brussels and the immigrants who were flocking to British shores. Trump, with his “America First” slogan, is making a similar case. As he said last week, “Our country lost its way when we stopped putting the American people really first. We got here because we switched from a policy of Americanism—focusing on what’s good for America’s middle class—to a policy of globalism.”

For Trump, however, nationalism is a harder argument to make. The U.S. may have entered unpopular trade deals (deals that Clinton now claims to oppose, too), but it hasn’t surrendered nearly as much sovereignty to international institutions as has the U.K. What’s more, the United States, more than Britain, sees itself as a nation of immigrants. So when Trump says he’ll protect Americans against Mexican and Muslims, Democrats can respond that those immigrants are Americans, too. Pro-E.U. politicians couldn’t speak the same way about the Polish plumbers and Syrian refugees that the pro-Brexit campaign demonized.

The language is telling. In Britain, the “Remain” camp’s slogan was “Britain Stronger in Europe.” Hillary Clinton’s current slogan, by contrast, is “We’re stronger together.” The struggle over Brexit was a struggle between nationalism and internationalism. The struggle between Trump and Clinton is a struggle between different kinds of nationalism. It’s less about America’s relationship with the world than about who is really an American. That’s why Trump will lose a substantial number of voters who agree with him about NAFTA and Iraq. They may agree that the United States should pull back militarily and economically but they will never agree that Gonzalo Curiel and Barack Obama aren’t real Americans.

God help us if they do.

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