The New Yorker recently attempted to explain two “populists” running for president, the only candidates generating huge and enthusiastic audiences. Instead, the article’s snide tone reflected the nearsightedness of cosmopolitan elites. Both candidates were mislabeled as “populist.” Bernie Sanders is a democratic socialist; Donald Trump is a trash-talking billionaire. But the magazine also mangled the true historical meaning of populism.

The writer seemed to be channeling Richard Hofstadter, the Columbia historian who back in the 1960s famously put down populism and other rebellious movements as “the paranoid style in American politics.” People are irrational, Hofstadter explained, driven by delusional fears and conspiracy theories. Not to be trusted with governing power.

Class condescension is as old as American democracy and is back in vogue this season, thanks mainly to the plutocrat with big hair. Only, Donald Trump turned “populist” anger upside down. He’s a super-rich guy ridiculing the “stupid” people in government and bragging about how he and his fellow billionaires buy politicians to get free stuff from government. Sanders, meanwhile, is plowing a parallel furrow of dissent—a substantive and serious program for reform.

But neither fits the label “populist” because they are both working within the established order. By definition, populism requires plain people in rebellion, organizing themselves to go up against the reigning powers. Major pushback from fed-up people is not present—not yet anyway—but the great disturbances already roiling party politics suggest that the political status quo is vulnerable to more upheavals, particularly if timidity and stalemate continue to suppress meaningful change.

It depends, first, on whether the 2016 results promise real changes in economics and social equity and/or convince people they have to dump both parties and attempt power-seeking politics of their own. This is a tender moment for the two-party system. ...