It was in 1931 that the historian James Truslow Adams coined the phrase “the American dream.”

The American dream is not just a yearning for affluence, Adams said, but also for the chance to overcome barriers and social class, to become the best that we can be. Adams acknowledged that the United States didn’t fully live up to that ideal, but he argued that America came closer than anywhere else.

Adams was right at the time, and for decades. When my father, an eastern European refugee, reached France after World War II, he was determined to continue to the United States because it was less class bound, more meritocratic and offered more opportunity.

Yet today the American dream has derailed, partly because of growing inequality. Or maybe the American dream has just swapped citizenship, for now it is more likely to be found in Canada or Europe — and a central issue in this year’s political campaigns should be how to repatriate it.

A report last month in The Times by David Leonhardt and Kevin Quealy noted that the American middle class is no longer the richest in the world, with Canada apparently pulling ahead in median after-tax income. Other countries in Europe are poised to overtake us as well.