Trump campaign reveals class barriers.

• Position: Your Life

Whatever you think of Donald Trump, his presidential campaign has forced American elites, both liberal and conservative, to confront the growing class divide that is fracturing this nation. This is not the rather porous divide between the one percent and 99% that alarms Progressives such as Bernie Sanders, notes Randal O'Toole, senior fellow with the Cato Institute, Washington, D.C., in an article appearing in the Washington Examiner.

Instead, it is the increasingly steep barrier between the 30% of working-age Americans who have college degrees and knowledge-based occupations and the 70% who do not have college degrees and, if they have jobs at all, mostly have manual labor-based occupations. Sociologists traditionally call the former group middle class and the latter working class.

The middle class has worked hard to design a society that works for it, but not for the working class, maintains O'Toole, author of American Nightmare: How Government Undermines the Dream of Homeownership. Fifty years ago, the distinction between middle class and working class was disappearing into a "middle-income" group, as working-class incomes were a substantial fraction of, and, in some places, equal to, middle-class incomes. Cultural divides were falling as working-class families "lived in the same neighborhoods, drove similar cars, watched similar TV shows, and ate similar foods as middle-class families."

This happened because the U.S. after World War II was the industrial powerhouse of the world, while other industrial nations were rebuilding. By the 1970s...