The United Kingdom, where I live, has just voted to leave the European Union after a campaign on the Leave side argued that “people in this country have had enough of experts.” Language and economics were a crucial part of the Brexit divide. The economic experts were all lined up on the side of the Remain campaign, in a near-total unanimity that was signaled when President Obama visited Britain to restate and reinforce the consensus view — a highly unusual intervention in another country’s democratic politics. All the insiders said very similar things in very similar language. It had no traction: the alphabet soup of I.M.F., O.E.C.D., E.C.B. and all the other experts might as well have been talking entirely to themselves. When the electorate voted the other way, it was as if the very unanimity and certainty of the expert consensus was somehow off-putting. Project Fear, as the Remain campaign was dubbed, seemed to be too certain about its predictions and projections, many of which came with suspiciously precise numbers attached, like the claim that Brexit would cost £4,300 ($5,300) per household. To a lot of voters, that certainty looked fishy. If economics is so good at forecasting things, how come nobody saw the credit crunch and Great Recession coming?

“It’s not free trade, it’s stupid trade,” Donald Trump has said during his presidential campaign — a slogan that contradicts every tenet of mainstream economics, as well as a quarter of a millennium of accumulated economic data. It is also a phrase that immediately resonates with a big chunk of the electorate. They know what it means. The five million American manufacturing jobs that have vanished since 2000 aren’t coming back. The idea that Nafta is “the single worst trade deal ever signed” might have no expert support, but if you live in a one-industry town and the main workplace has closed, you are unlikely to agree with the professional consensus instead of your own lived reality of loss and decline. Words like “stupid” and “worst” and “losing” — people know what they mean. They can feel it in their marrow.

Research has shown that the single greatest predictor of how people voted in the Brexit referendum was their education level: the more education, the more likely to vote Remain; the less, the more likely to vote Leave. In America, Trump has newly polarized many voters along educational lines, in the same manner that Brexit did. The educated and uneducated are increasingly living in parallel societies, each with different experiences, philosophies, expectations, trajectories and language. This isn’t the same as the divide between rich and poor, because in a society with shared assumptions, the poor can dream of being rich and sometimes can even manage it. Anyone can make it: That’s the American dream. Today, though, to the excluded, economic success looks like a club membership, exclusive by definition and design.

It would be a disaster for democracy if this divide were to become permanently entrenched. Democracy depends on an informed electorate; it depends on argument, and that in turn depends on having enough in common to be able to argue. Bankers and the financial elite can’t just talk to each other as if nothing has changed; as if the little people are just going to accept that they can’t follow the big words, so the rich should just keep running things in their own interest. The experts need to set terms for the debate that everyone can understand. So yes, when it comes to economics, language matters. In case you’re wondering, the Flesch-Kincaid grade level of this column is 9.6.