Mr. Trump, after all, was always an unlikely populist, a self-proclaimed billionaire with a private plane and gilded estates. Mr. Trump, who by one count switched political parties seven times before last year’s campaign, seems less driven by ideology than by instinct borne out of his own resentment of elites who, in his view, have never given him the respect he deserves.

“Bannon gave him a worldview to sink those emotions into, to connect those emotions into,” said Michael Kazin, a historian at Georgetown University and author of books on populism and William Jennings Bryan. That does not make Mr. Trump the second coming of Jackson, he added. “The only comparison, as Bannon knows, is there’s a toughness, there’s a running against the entrenched, educated elite. That part’s true.”

Mr. Trump’s election, coupled with the British referendum to leave the European Union and the rise of anti-establishment parties in Europe, has focused renewed attention on the power of populism in Western societies. Authors have rushed out a shelf full of books, and contracts for more are still being signed; universities and think tanks are awash in panel discussions.

Populism can be found on the political right and left, often fueled by economic disparities, a sense of dislocation and anger at elites. In the United States, populism after Jackson gained steam in the 1890s with the formation of the People’s Party and Bryan’s presidential campaigns. It was revived in the 1930s by Huey Long and his Depression-era Share the Wealth Clubs and had a brief return in the 1990s with Ross Perot’s independent campaigns.