“My government will respect fully the domestic electoral process in the United States,” Peña Nieto said. He neither rescinded nor repeated his comparison of Trump to the World War II-era fascists, instead warning more generally about “political actors using populism and demagoguery.”

Both Peña Nieto and Trudeau were pointedly trying observe the diplomatic tradition of not taking a public position on elections inside another country, even if their statements in other venues have made it obvious they are rooting for Hillary Clinton. And although he has endorsed Clinton, Obama criticized Trump only implicitly as he defended America’s tradition of welcoming immigrants and the trade agreements Trump has trashed on the campaign trail.

But at the very end of the press conference, Obama dropped the facade. He took issue with a reporter who referred to Trump’s “populism” in a question to the other leaders about his appeal to voters opposed to trade agreements like NAFTA and Obama’s Trans-Pacific Partnership. “I’m not prepared to concede the notion that some of the rhetoric that’s been popping up is populist,” he said. (Obama still wouldn’t use Trump’s name, but it was apparent that the president was talking about him.) He contrasted his own record of supporting policies to reduce income inequality with the record of “somebody else who has never shown any regard for workers, has never fought on behalf of social-justice issues.”

They don’t suddenly become a populist because they suddenly say something controversial in order to win votes. That’s not the measure populism. That’s nativism. Or xenophobia. Or worse. Or it’s just cynicism.

Obama singled out Bernie Sanders as someone who “I genuinely feel deserves the title” of a populist, “because he’s been in the vineyards fighting.” And although he’s not on the ballot this year, the president was adamant about his own populist credentials. He brought up the auto bailout he presided over early in his tenure, a move that he said was not popular “even in Michigan” at the time. “Maybe that was an elitist move on my part because it didn’t poll well,” Obama said.

Then he turned back to Trump. “Somebody who labels ‘us versus them’ or engages in rhetoric about how we’re going to look after ourselves, take it to the other guy, that’s not the definition of populism,” the president said.

When he was done, Obama realized he had perhaps gone on a bit too long, hijacking a press conference devoted to energy and climate issues and aimed at highlighting the close relationship among the three nations of the continent. “Sorry,” the president said. “This is one of the prerogatives when you get to the end of your term. You go on the occasional rant.”

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