Some "Brexit" backers are gleeful that "elite" pundits, pollsters, investors and even bettors didn't predict the outcome of last week's vote.

Other now-sheepish Brexit supporters have expressed regret, and some even want a revote.

And even more stunning than the unpredicted result is the fact that prominent politicians backing Brexit — including Boris Johnson, the leader of the "Leave" campaign who was thought to be Britain's next prime minister until he backed out on Thursday — had no contingency plan should Brits buy their bogus "leave" arguments.

In fact, Johnson and Nigel Farage, the irrepressible, irresponsible force behind the United Kingdom Independence Party, have already backpedaled on promises they made during their Brexit campaign.

The resulting political and economic chaos is reverberating well beyond Britain and the European Union. Trillions were lost in equity markets before a recent rally. And European leaders committed to the union are struggling for a policy response that can accommodate Britain while stanching other nascent anti-E.U. movements.

Britain may not only lose the political, diplomatic and economic benefits of E.U. membership, but potentially Scotland and even Northern Ireland in the process, should those countries seek a future tied to their European brethren.

Meanwhile, both major U.K. parties are in turmoil. The Conservative Party that produced Winston Churchill and Margaret Thatcher is now led by a lame-duck prime minister who promised a plebiscite in order to win an election. Now David Cameron has lost Brexit, and soon his post, sparking a succession crisis. And the Labour Party is no longer led by the likes of centrist Tony Blair, but by leftist Jeremy Corbyn, whose lackluster "Remain" campaign lost him a no-confidence vote.

The dislocations of capitalism, globalism, immigration and other challenges that propelled Brexit are also driving the debate in America's 2016 campaign. Candidates are appropriately focusing on these issues because they impact the very fabric of American life. But all too often, the debate is all heat and no light. Case in point was Donald Trump's Tuesday speech railing against free trade agreements and globalism itself.

Among other pledges, Trump threatened to withdraw from the North American Free Trade Agreement, label China a currency manipulator, and impose extra tariffs on Chinese products. Those stances were blasted by the National Association of Manufacturers and the U.S. Chamber of Commerce, which claimed Trump's approach would cost 3.5 million U.S. jobs and result in higher prices and a weaker economy.

Like the Brexit rhetoric, Trump's speech had few specifics on what would replace the integrated international economic infrastructure that has developed over decades. As Brexit so painfully makes clear, unraveling these institutions can unleash a new set of problems that can exacerbate the challenges of those already dislocated by globalism.

Governing is not campaigning. And campaigning should not contain the xenophobia and outright misinformation that characterized the Leave campaign — and at times Donald Trump's campaign, too.

U.S. voters should heed Brexit's lesson and hold politicians to higher standards. Britain is politically, diplomatically and economically important. But it has a relatively limited impact on geopolitics and geoeconomics. The same cannot be said for the U.S., and a Brexit-like result without well-developed alternatives could create conditions akin to the 2008 financial crisis — or worse.