Across the postindustrial world, the populist right is excelling in the old bastions of the left.

If there is a lesson for the United States in the decision by British voters to exit the European Union, it is the importance of the emerging split between the beneficiaries of multicultural globalism and the working-class ethno-nationalists who feel left behind. These issues have the potential to overcome longstanding partisan ties, even in the United States.

The power of these issues was evident in the British referendum Thursday evening as the votes were counted. The result in Sunderland — long a Labour stronghold, which voted 62 percent to “Leave” — was the first clear sign of the final outcome.

In the end, many of Labour’s traditional working-class strongholds in old industries across northern England voted for “Brexit.” (The last deep coal mine in the country closed last year in North Yorkshire, in northern England.)

“Remain” did better than the Labour Party normally does in the establishment-friendly, traditionally Conservative and more affluent countryside of southern England, let alone in the Conservative seats of London, but not by enough.