Leaders on the Democratic left who want to represent the have-nots face an obstacle: their own voters.

Keith Ellison, a congressman from Minnesota and a candidate for the chairmanship of the Democratic National Committee, argues that Democrats “have to stand for a strong, populist economic message.” He warns that “the way the working class is always controlled is that it’s divided.”

A key Ellison supporter in the fight for the chairmanship, Senator Bernie Sanders, believes that

Democrats are focused too much with a liberal elite, which is raising incredible sums of money from wealthy people in the upper middle class, but has ignored to a very significant degree the working class and the middle class and low-income people in this country.

For a certain stripe of liberal Democrat, free trade agreements have become emblematic of what Sanders describes as

a global race to the bottom to boost the profits of large corporations and Wall Street by outsourcing jobs; undercutting worker rights; dismantling labor, environmental, health, food safety and financial laws; and allowing corporations to challenge our laws in international tribunals rather than our own court system.

The problem facing Ellison, Sanders and their allies is that despite the success of Sanders’s presidential campaign, the Democratic electorate has actually become less receptive to populism over the past two decades.

Mark Muro, the director of the Metropolitan Policy Program at Brookings, analyzed the differences between those communities that supported Hillary Clinton and those that backed Donald Trump. The findings of Muro and Sifan Liu, a Brookings research assistant, suggest that Democrats who are calling for a return to progressive populism will encounter more hurdles than they expect.