The people had finally found their leader, a champion for those who had built the country with their hard work and yet now believed themselves to be silenced and ignored — left behind by the artificial currents of contemporary life. He would make their voices heard again. They didn’t think of themselves as angry — at least not without a good cause — but they were no longer going to go gently into that political good night.

The year was 1896, and a new century loomed just four years away. They believed they had one last chance to change the errant course on which the country was set, and William Jennings Bryan was ready to lead them.

Manning the Barricades

With the triumph of Donald Trump in the 2016 presidential election, magazines from Vanity Fair to The Economist suddenly began writing about populism and trying to analyze that amorphous identity that periodically returns to American politics. Far less defined than a political movement or agenda, American populism is an impulse, rooted in Jeffersonian individualism and animated by a conviction that something essential in our culture is under siege by powerful currents in the wider world.

While politicians may choose to use populist rhetoric to rally their voters, it’s not an identity that many would choose on their own, because it’s borne of crisis, understood by those who take it up as being nothing less than a state of emergency. Populism amounts to a last desperate manning of the barricades, when all others have decided to jettison something that, in a significant number of hearts, is still worth fighting for.

The populism of the 1890s came at a crucial moment of transition from one economic framework to the next, as an America of farmers and craftsmen was giving way to an America of industrial workers, leviathan corporations, and new immigrants. Today, the country faces another transition to a more interconnected and, some say, post-national world, and populists have again reappeared, fearful of rocky shoals along the passage. The impulse is no longer tied to the agrarian identity and way of life that was so tenaciously defended by populists at the close of the 19th century, but it is now expressed by those for whom something just as sacred is at stake.

Cultural Power

More than economic or political power, cultural power — the power to define what ought to be the true iconic representation of America, from which comes ideas of right and wrong — has always lain at the heart of populism, even if more specific economic concerns are easier to identify. This is why the emergence of a multi-billionaire as populist champion isn’t as baffling as it would be if the primary engine was class-based resentment of the wealthy (and it’s why Bernie Sanders is actually less of a populist than Trump).

Learn More: Donald Trump: The avatar of democracy

As historian Alan Brinkley showed in his book Voices of Protest, despite the ways that the populist impulse has varied among its adherents throughout the decades, its “central, animating spirit” remained the determination to restore “to the individual the control of his life and livelihood.” Brinkley notes that Depression-era rousers like Huey Long and Charles Coughlin connected “their messages so clearly with the residual appeal of the populist tradition,” and future historians will undoubtedly note the same about Donald Trump.

But his current success shows that its appeal is not merely residual but continues to animate millions of people. The lesson of Trump’s surprise victory is that populism remains at its core an evergreen cultural force that is as intertwined with our ideas about democracy as notions about voting, representation, civil rights, or economic fairness.

Today’s drive toward populism is not primarily because of big business or big banking, but because of a perceived threat of similar size and danger to the concept of Jeffersonian individualism. Now it is the cultural triumph of identity politics that’s pushing people toward populism, as surely as monopoly and industrialization did 120 years ago. Ascendant globalism is another: just as the farmers of the 1890s felt displaced from what they considered their time-honored position within the country’s culture and economy, those who recently rallied to the populist tone of the current president felt much the same.

In his 1955 Pulitzer Prize-winning book The Age of Reform, Richard Hofstadter mused that “While its special association with agrarian reforms has now become attenuated, I believe that populist thinking has survived in our own time, partly as an undercurrent of provincial resentments, popular and ‘democratic’ rebelliousness and suspiciousness, and nativism.”

Indeed, Hofstadter’s account of those who flocked to William Jennings Bryan in 1896 is a caustic one and caused an outcry among historians who had long looked upon the populists as virtuous Jeffersonian Democrats. But Hofstadter substantially changed the way the mainstream thinks about our periodic outbursts of populism, and today, charges of nativism, provincialism, and intolerance are even more commonly attributed to Trump’s supporters than to Bryan’s.

Canaries in the Coal Mine

I don’t believe populism is inevitably as xenophobic as that, but I do believe the impulse is inherently defensive. The Economist recently reported that populism in Alabama “has not always been driven by prejudice, as might be supposed.” Rather, explained the former director of the Alabama state archives, populism is always and everywhere fired by fears of “the rise of a new aristocracy,” and Alabamans who turned to populism were “not simply emotional victims of demagogues.”

Contemporary ideologies that divide people into grievance groups are a cultural echo of the process of industrialization that once divided people into competing economic classes. In both, the deck is stacked against the individual. The proper response to populism isn’t to dismiss it as fringe, bigoted, or anti-intellectual, but to remember that threats to individualism come from every angle, sometimes in unexpected ways. Populism is the canary in our political coal mine — a warning that individual liberty may be having its oxygen drained away. Those who are concerned about freedom should pay attention to it.