For the first time in a generation, Latin America appears to be moving in the right direction again.

Administration officials, congressional leaders and U.S. business executives are aware of this. The unspoken concern among many, however, is that the White House—wittingly or unwittingly—will do something that sidetracks the reform process.

That’s also a concern south of the border. The impression throughout the region is that President Trump’s only interests in the region are curtailing immigration, eliminating or severely restricting the North American Free Trade Agreement (Nafta), and undermining Venezuela’s socialist dictator, Nicolas Maduro.

If that’s true, the president is missing the most important story coming out of Latin America: the widespread backlash against left-wing authoritarian populism and the embrace (admittedly, in varying degrees) of liberal democracy, free-market economics and globalization.

Consider Mexico, which will be holding presidential elections next year. Andres Manuel Lopez Obrador, a left-wing nationalist demagogue and longtime critic of the United States, is leading the opposition and ahead in most polls right now. If anything, he’s being aided by the White House’s perceived hostility toward Mexican immigrants and, particularly, its open hostility toward Nafta.

Lopez Obrador’s opponent is expected to be Jose Antonio Meade, a political independent who just resigned from his post as Mexican finance minister to pursue the nomination of the ruling Institutional Revolutionary Party.

A Yale-educated economist who has served as a Cabinet minister under both President Enrique Pena Nieto, the incumbent, and Felipe Calderon, Nieto’s conservative predecessor, Meade is a very reasonable guy with whom any White House surely would prefer to deal than Lopez Obrador.

Yet President Trump’s actions and ill-considered rhetoric could help put Lopez Obrador in office.

The White House also risks undermining progress being made elsewhere.

For example, Argentina, Brazil and Peru all have new governments, much friendlier to the United States than the previous regimes. Ecuador’s president has turned against his populist predecessor, who helped to put him in office. Bolivia’s socialist strongman, Evo Morales, is running into strong opposition as he tries to rig the law to pave the way for his re-election. And businessman Sebastian Pinera appears poised win the presidency of Chile, a position he held from 2010 to 2014, rectifying that country’s crooked trajectory of recent years.

In addition, the Latin American community, led by the so-called Lima Group—which includes Argentina, Brazil, Canada, Chile, Colombia, Costa Rica, Guatemala, Honduras, Mexico, Panama, Paraguay and Peru—has taken a tough stand against Venezuela’s continuing human-rights abuses and contempt for the rule of law.

People in the administration, in Congress and in the business community seem well aware of these positive changes. Why isn’t the message getting through to the White House?

It’s been a long time since most of Latin America shared America’s values and was a place with which the United States could do meaningful business.

Not since the idea of a Free Trade Area of the Americas emerged (to be destroyed later by a minority of left-wing populists) has there been a better climate for reconnecting and integrating the economies of North and South America. Integration in this case means the elimination of as many barriers as possible to the circulation of goods, services, ideas and, yes, eventually, people.

There are—amazingly—plenty of people in Washington who share this vision and are not enemies of President Trump. Their hope is that real improvement in relations between the United States and Latin America will take hold. What is missing is the sense that the White House believes that these opinions and this vision are worth pursuing.

If the opportunity is missed, who knows how long it will be before Latin America once again is willing to embrace the values that made the United States what it is.

This is a once-in-a-lifetime deal that President Trump would be foolish to forgo.