The American middle class is facing an existential crisis. For more than three decades, declining wages, fraying benefits, and the rising costs of education, housing, and other essentials have stressed and squeezed middle-class Americans. But by far the biggest threat to middle-class workers—and to our economy as a whole—comes from the changing nature of employment itself.

Gone is the era of the lifetime career, let alone the lifelong job and the economic security that came with it, having been replaced by a new economy intent on recasting full-time employees into contractors, vendors, and temporary workers. It is an economic transformation that promises new efficiencies and greater flexibility for “employers” and “employees” alike, but which threatens to undermine the very foundation upon which middle-class America was built. And if the American middle class crumbles, so will an American economy that relies on consumer spending for 70 percent of its activity, and on a diverse and inclusive workforce for 100 percent of the innovation that drives all future prosperity.

This crisis is not unfolding in a vacuum. For more than 30 years, the Democratic Party has suffered from a crisis of identity, leadership, and vision on issues of political economy that has left it unable to either articulate or defend the true interests of the middle class. Democrats might tinker around the edges arguing for more economic justice and fairness, but for the most part they have largely accepted, or at least failed to counter, the fictitious trickle-down explanation of what growth is (higher profits) and where it comes from (lower taxes and less regulation). And so, through Republican and Democratic administrations alike, corporate America has seen less regulation, lower taxes, and higher profits, while middle-class America has gotten the shaft.