LONDON — If anyone still needed a reminder that the phrase “it can’t happen here” should be struck from the lexicon of 2016, Britain’s historic Brexit referendum provided one more dramatic piece of evidence. The question is how Hillary Clinton and Donald Trump and their allies interpret the results of what did happen here.

The decision by British voters to take a leap into the unknown by severing ties with the European Union is by no means a reliable predictor of the eventual outcome of the presidential election in the United States. But neither was it an event without larger meaning.

Frustration with political elites knows no borders today. There are signs of it across Europe, just as there have been signs of it in the United States in recent campaign cycles. What erupted here this week is stirring elsewhere. It has defied conventional thinking and disrupted conventional analyses. Who’s to say there are no more significant shocks ahead?

Here’s one example of a connection between what happened in Britain and the rise of Trump in the United States: In Britain, nearly the entire political establishment was aligned in favor of staying in the European Union. The “remain” campaign was in some measure an effort by these political elites to scare rank-and-file voters with dire forecasts about what a post-Brexit economy might look like that included threats of spending cuts and higher taxes.

But when voters went to the polls, in a huge turnout, they either weren’t afraid of those forecasts or didn’t believe what they had heard because they had given up on the political leaders of their country. In either case, it was an explicit rejection of what they were being told and an embrace of their own instincts and personal experiences.

How does that relate to the presidential campaign? Ask Peter Hart, the Democratic pollster who has conducted focus groups of Republicans, Democrats and independents in this and previous campaign cycles under the auspices of the Annenberg Public Policy Center of the University of Pennsylvania.

Outside Pittsburgh last week, he assembled a group of voters who fit the model of potential supporters of Trump. The session came after Trump had experienced a series of self-inflicted wounds – bad enough, Hart believed, to give people pause about supporting the New York billionaire.

What he found instead were people who were far more forgiving than he had expected. They were willing to ignore or dismiss his gaffes, to explain away his mistakes and to focus instead on something he did that they liked. “It just shocked me,” he said.

The Brexit vote is the kind of event that should make both the Clinton and Trump campaigns pause and take notice. As they began to respond Friday, it was clear that both had seized on aspects of the British result that reinforced some of their basic instincts.

Clinton issued a carefully worded statement respecting the decision of the British voters to break with the EU while restating the importance of the long-standing relationship between the two allies.

She also said this as a way of trying to discredit her opponent: “This time of uncertainty only underscores the need for calm, steady, experienced leadership in the White House to protect Americans’ pocketbooks and livelihoods, to support our friends and allies, to stand up to our adversaries, and to defend our interests.”

Trump also touched on the close ties between the United States and Britain, but his statement highlighted themes quite different from Clinton’s, themes straight from his own message.

“The people of the United Kingdom have exercised the sacred right of all free peoples,” he said. “They have declared their independence from the European Union and have voted to reassert control over their own politics, borders and economy.”

Arriving for the grand opening of his refurbished golf course in Scotland, Trump put it more bluntly. “They took their country back,” he said. “That’s a great thing.”

David Axelrod, the chief strategist in President Obama’s two campaigns, said some caution is needed in interpreting the meaning of the Brexit vote before knowing what, if anything, it means for American politics. But he cited two things of note for Clinton.

“One is, if this has negative implications for the U.S. economy between now and November, that’s a bad thing” for Clinton, he said. “Two, if it creates a sense of instability, that may be a good thing for her in an election where there’s a great deal of concern about whether Trump is up to handling crises.”

Trump ally Newt Gingrich, the former speaker of the House, cast the Brexit vote as an almost wholly positive outcome for the presumptive Republican nominee. “This vote is about national identity. It is about anti-bureaucracy in Brussels. It is about immigration, and it is about the right to promote your own future,” he said.

Gingrich added: “So Trump gets up this morning and says, ‘Anti-bureaucracy, anti-immigration, set your own destiny, fight for your own economic future and quit letting foreigners tell you what to do.’ That’s where Brexit works for him.”

Gingrich said Clinton can’t plan to fall back on her experience or claim to be steadier in a crisis to counter Trump’s populist appeal. He pointed to her advocacy of intervention in Libya, her call for a reset with Russia and other aspects of her tenure as secretary of state. “She has a record,” he said. “She’s not just a candidate being reinvented.”

Axelrod conceded that in an anti-establishment environment, Clinton would have difficulty presenting herself as a change candidate: “At the end of the day, what she’s selling is confidence, stability, seriousness.

“Trump certainly has tapped into those primal forces. The question is whether they’re strong enough to overcome serious questions about his temperament and preparedness.”

Conventional thinking suggests that Trump will somehow disqualify himself in the eyes of too many voters, a novice politician who doesn’t take seriously enough the role and responsibility of being a presidential nominee.

But Hart said, “Obviously, if he has something to say, there’s an audience willing to listen to him.”

The parallels between Brexit and the U.S. presidential election only go so far. One is an up-or-down vote on a proposition, an idea, an action. The other involves more complicated judgments about individual candidates.

Brexit was decided on the basis of a tally of the popular vote. Presidential races are decided by political geography and electoral votes.

But the broader message from the Brexit vote goes beyond the economic and political turmoil it has touched off here. This is a time of political instability in which the old anchors and guideposts have been dramatically weakened. Politicians who ignore this, who think conventionally, who don’t find ways to understand and address it, will be taking foolish and unnecessary risks.