President Trump leaves a meeting with House Republicans at the Capitol on Tuesday. (Matt McClain/The Washington Post)
Marc Fisher, a senior editor, writes about most anything. He has been The Washington Post’s enterprise editor, local columnist and Berlin bureau chief, and he has covered politics, education, pop culture and much else in three decades on the Metro, Style, National and Foreign desks.

Three years after Donald Trump rode down his golden escalator to present himself as the great hope of a new American populism, his detractors are increasingly betting that Trumpism will end in a dramatic confrontation between the president and the investigators examining how he won office. Some, like the New Yorker’s Adam Davidson, say Robert Mueller’s team will lift the fog from Americans’ eyes and lead us back toward a sober embrace of the very institutions that voters rebelled against when they chose a populist disruptor. Some, such as the Atlantic’s Caitlin Flanagan, say reports about the president’s sordid behavior (alleged affairs with porn actresses, among other things) will break the populist fever. Others hope that a snowballing of policy outrages — thousands of traumatized children held in tent camps, for example — will smother Trumpism.

But the history of populist movements tells a different story. When citizens rise up against a system they believe is broken, when voters conclude that they’ve been conned or taken for granted, they are generally not dissuaded by their leaders’ personal peccadilloes, nor are they impressed by investigations that reveal misdeeds by their populist flag-bearers.

President Trump remains as polarizing a figure as ever — a paragon of possibility for his supporters and the leader of an anti-democratic demolition crew to his detractors. But any blue wave approaching the shores of power this fall is likely to be modest in size, and the populist fever that swept Trump to office is still quite a ways from breaking.

In the United States and other Western democracies, populist uprisings, even when they seem to come from nowhere, usually turn out to have been a long time brewing. Trumpism, in many ways, is the ultimate expression of a frustration that had been growing among Americans, from Barry Goldwater and Eugene McCarthy in the 1960s to Pat Buchanan and Ross Perot in the 1980s and ’90s and on to the historic election of Barack Obama in 2008.

And just as they emerge over a long stretch of time, populist movements also dissipate slowly. They die not simply because of corruption investigations, dogged news coverage or bad behavior by the movements’ leaders. Rather, there seems to be a natural process, a pattern of political change that transcends personalities and places. Even when leaders of such movements prove to be less effective or attractive than they seemed at first blush, the political and economic forces that brought them to power tend to protect the movements longer than their opponents might expect. Abroad and at home, populist movements end when the ideas that fueled them are absorbed into mainstream institutions or when the conditions that sparked their outburst are elementally altered.

For years, outsiders argued that Italian populist leader Silvio Berlusconi could not survive atop his country’s notoriously volatile government for long. After all, although Berlusconi was a master of media messaging who was allergic to ideology and had a knack for mirroring the passions of the people — sound familiar? — he was also a bully who favored his own business interests and was constantly fighting off investigations of corruption and sexual impropriety.

But Berlusconi lasted 17 years as Italy’s dominant political figure before he was forced to resign as prime minister in 2011. The public grew weary of his show — the scandals, the media circus, the sordid indignities of his personal life. Yet even after the man was out of office, his message continued to resonate in Italian politics. His skepticism of globalization and his anti-immigration rhetoric, for example, remain at the core of the country’s populist movement.

Similarly, in Austria, Joerg Haider rose from the political fringe to become the country’s most important postwar right-wing populist figure, even as he fought off a steady stream of investigations into money laundering, embezzlement and other corruption allegations. Haider died in 2008 having effectively broken his country’s major parties, reshaping Austria’s political landscape and establishing an anti-immigrant nationalism as an enduring, animating force in politics.

In the United States, the history of populist uprisings is a story that, over and over, ends with absorption and co-option. The socialist movement of the early 20th century never captured the White House, but the ideas that Norman Thomas and other socialist leaders pushed in a time of stark economic inequality became essential parts of Franklin Roosevelt’s New Deal: Social Security, unemployment benefits, jobs programs.

Half a century later, on the other side of the ideological spectrum, Ronald Reagan similarly adopted positions first staked out by the harshly conservative and deeply unpopular Goldwater. Goldwater’s 1964 presidential campaign made a classic populist appeal aimed at what he called a “hidden majority” of frustrated Americans, promising to slash regulations and taxes, reduce government’s role, and leave civil rights questions to the states. Goldwater suffered a historically lopsided loss, but 16 years later, Reagan rode many of those ideas to a big victory.

And that, argues three-time populist presidential candidate Pat Buchanan, is how populist movements both end and succeed. When someone comes along to “capture those ideas and ride them to power,” the populist movement fizzles because it’s no longer necessary — the people have, in a sense, been heard, said Buchanan, who sought the White House from 1992 to 2000. “The populists are the canary in the mine. They do not survive,” he said. “But their ideas do. FDR and Reagan knew how to seize on those ideas and make them palatable to a majority. Today’s establishment doesn’t seem to know how to do that.”

Of course, Roosevelt and Reagan didn’t adopt populist ideas or methods whole-hog. They adapted the issues and tapped into the emotions that drove the movements, all in a way that they expertly fit into the institutions that bind American society.

Kathy Cramer, author of “The Politics of Resentment,” has spent countless hours with Trump supporters in Wisconsin, exploring the edges of their political decisions. “We shouldn’t expect people who voted for Trump to say, ‘Yeah, you’re right, I made a mistake,’ ” she said. “So often, they preface their support of him with, ‘Well, I wish he didn’t behave like that.’ They don’t love him. But I don’t see signs of embarrassment. They see the investigation and the news media as conspiring against Trump. They still want respect, to be heard, to not be looked down on.”

The endgame Cramer imagines is the emergence of a Republican “who gives people a way to shift from Trump in a way that allows them to save face. They do eventually want something to turn toward, and I don’t see what that is. I sure don’t see what the Democratic Party is offering as an alternative.”

In theory, the next phase of U.S. politics might feature a new FDR or Reagan emerging to extract powerful ideas from Trumpism and build onto that structure a message that brings Americans together. But such a unifying push is not inevitable, and proponents of a new American nationalism, such as Trump’s former chief strategist Stephen Bannon, contend that the chapter after Trumpism will be avowedly anti-immigration, pulling the country back from the multicultural future envisioned by the three previous presidents. Nativism does not lend itself to adaptation into some less polarizing political movement.

Still, a follow-on to Trumpism could take any number of forms. Either a Democrat or a Republican could cobble together an appeal that incorporates Trump’s skepticism of the excesses of political correctness and identity politics while rallying Americans toward a more welcoming approach to immigration, picking a fight with tech companies over the future of work, and returning to an embrace of science and internationalism.

Trump was elected to disrupt and dismantle — the classic aims of many populist leaders. He has already dashed Democratic hopes that the Obama presidency had ushered in a new multicultural majority; he has also redefined the Republican Party as something far from its half-century of conservatism and given Americans their first view of what a cult of personality looks like in the White House.

But the leader of a populist movement is often so far outside the political norm that he turns out to be a one-shot. There is, after all, no obvious next Trump in either party. Yet the passions that made the populist personality attractive in the first place often survive the leader’s fall.

Sen. Joseph McCarthy’s red-baiting crusade of the 1950s remained popular long after the press and members of Congress turned against him. Decades later, some historians would suggest that had news coverage of McCarthy been more aggressive, much earlier, his effort might have waned sooner. But as Edwin Bayley showed in his 1981 book, “Joe McCarthy and the Press,” there was no lack of truthful, clear reporting: “Almost every aspect of McCarthy’s record was investigated and his derelictions exposed, over and over. No one cared,” Bayley concluded. “. . . It was not McCarthy’s character, morals, or deportment that concerned people; the only issue that mattered was the Communist issue.”

McCarthy, like Trump, preached skepticism and disbelief, railed against the news media and investigators, and sowed doubt about the very nature of expertise and fact. A cavalcade of criticism and investigation led McCarthy’s supporters to stick by their man, just as we see today.

Any pivot from that doubling down to an endgame is likely to involve the passage of enough time to get past the powerful obstacle of pride. The more that Democrats press Trump voters — and Republicans in Congress — to admit that their leader is problematic, the less likely they are to do so.

Is there anything a Mueller report could say that would turn Trump’s hard-core supporters against him now? It’s unlikely that the forces that got him elected will dissipate until traditional institutions, those his supporters feel abandoned by, begin to deal with the structural problems beneath the populist impulse. There are still a lot of deeply frustrated voters out there.

marc.fisher@washpost.com

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