Few American politicians have provoked such devotion and recrimination at the same time. But Long has one notable modern counterpart: Donald Trump. In many ways, his final years paralleled Trump’s 2016 campaign and presidency. Both men rose to national political prominence in the aftermath of a global financial crisis, with ethnic violence on the rise, automation putting workers’ jobs in doubt, and autocratic leaders gaining political power worldwide. Both made waves with sweeping populist rhetoric and policy proposals that challenged their parties’ more moderate establishments and promised to make government work for the common people. Both encapsulated their pledge to elevate the nation in a catchy slogan: Trump’s “Make America Great Again” and Long’s “Every Man a King.” And both, once in power, showed little concern for norms and standard legislative procedures when pursuing their goals.

But while Trump ran on a reactionary brand of populism, blending anti-establishment rhetoric and promises to restore prosperity and order with appeals to racist and nativist anxiety, Long pursued a progressive agenda and steered clear of the race-baiting common in Southern politics at the time. In this sense, Long is an interesting foil for Trump, who registered as a Democrat at several points in his life and expressed support for some typically Democratic policies even as he turned to the right. Though he died before he could run for president, much less take office, Long’s brief political career provides a mirrored vision of Trump’s demagogic populism—a glimpse of what could happen if a left-wing politician channeled a similar message and disregard for political mores.

Much of the appeal of that kind of populism cuts across eras and party lines. Mark Brewer, a professor of political science at the University of Maine, identifies several factors that have led American populism to gain traction in certain moments, regardless of political affiliations: perceived conflict between “elites” and “common people”; a sense of economic unfairness; distrust of centralized authority, particularly the federal government; and a desire to “maintain a previously existing arrangement that’s under threat and, in a lot of cases, probably gone already.”

Throughout American history, he says, populist voters have felt “a sense of a loss of control about what was going on in their society. Things were happening and things were changing, and the change was unsettling, but they couldn’t do anything about it. It was almost like they were being acted on from above.” That feeling has engendered the rise of parties and leaders, conservative or progressive, that promise to fight the system on behalf of average Americans.

Huey Long pledged to do just that throughout his contentious political career, and often delivered. While Trump has most aggressively leveraged his executive powers to manifest the anti-immigration plank in his populist platform, introducing a “Muslim ban,” radicalizing ICE, and, most recently, declaring a national emergency in order to fund a border wall, Long used his authority to establish public works programs for the poor. In his four-year tenure as the governor of Louisiana, Long built an extensive network of highways and bridges through the isolated rural areas of the state, expanded lower-class access to health care and education, and implemented strict new regulations in the state banking industry that improved consumer protections.