Council on Foreign Relations president Richard Haass said Friday that the United Kingdom's vote to leave the European Union should give Hillary Clinton's US presidential campaign a reason to worry.
Thursday's vote in favor of a British exit from the EU, or Brexit, signals a rise in the populism and nationalism on which US presidential candidates like Bernie Sanders and Donald Trump have built their campaigns.
"I think Mr. Trump will take some satisfaction - not just because he predicted it, but because the political, social, and economic forces that put Brexit over the top he will see as forces that are very close to his and Bernie Sanders' base," Haass said on a conference call.
"For Hillary Clinton's campaign, this is something of a warning not to underestimate this disaffection, not to underestimate political and economic nationalism" in the US, he added.
Trump, the presumptive Republican presidential nominee, and Sanders, Clinton's main Democratic challenger, were largely viewed as insurgent candidates in the 2016 presidential race.
Pundits for months didn't take Trump seriously and regarded his candidacy as somewhat of a joke. And Sanders was seen as somewhat of a symbolic candidate who was running mostly to highlight income inequality in the US. Though Sanders' prospects are all but dead, the Vermont senator still mounted a surprisingly significant challenge to Clinton, a former secretary of state who has made her career in politics.
If Clinton wants to ensure a win in the November general election, she now has to pay serious attention to the populist sentiments that gave rise to her rivals.
"The challenge for the Clinton campaign is going to be how to deal effectively with those kind of populist and nationalist concerns," Haass said. "The next 4 1/2 months in the US are going to some extent be informed by the perceived lessons and the perceived messages coming out of the Brexit vote."
As globalization and technological advances have made it more difficult for Western citizens to get jobs in their own countries, political candidates and referendums promising more isolation and independence have enticed voters.
"This is a lesson not to underestimate the degree of alienation a lot of citizens feel from their institutions and elected politicians, not to underestimate the anxiety that is associated with globalization and technological change," Haass said.
Jake Sullivan, the senior policy adviser for Clinton's campaign, said on a conference call Friday that the campaign was taking these sentiments seriously. But he also repeatedly emphasized the point that the US and UK were different countries.
"Far from underestimating what is happening out there, Sec. Clinton is seeing this, feeling it every day with her engagement with the American people, so many of whom believe that nobody has their back," Sullivan said, acknowledging that "a sense of deep frustration and alienation on behalf of the voters" was part of the reason the British chose to leave the EU.
Still, Sullivan said: "There are other factors as well, and Hillary Clinton is focused on not what's happening in the United Kingdom, but rather, what is happening in the United States, what are the uniquely American challenges we are facing and what are the uniquely American solutions that we can bring to address those problems and help working families get ahead."
Trump seems to agree with Haass. He said Friday that he saw a "big parallel" between what's happening in the UK with the Brexit vote and what's happening in the US with the 2016 election.
"People want to take their country back," Trump said. "They want to have independence in a sense. And you see it with Europe, all over Europe. You're going to have more than just ... what happened last night."