U.S. Secretary of State Rex Tillerson was welcomed by Mauricio Ibarra Ponce de Leon, North America director of Mexico’s foreign ministry, and U.S. Ambassador to Mexico Roberta Jacobson as he arrived in Mexico City Wednesday. President Trump has sent Tillerson and Homeland Security Secretary John Kelly to Mexico on a fence-mending mission made all the more challenging by the actual fence he wants to build on the southern border. (The Minnesota Star Tribune)

A frosty reception in sunny Mexico City awaited U.S. Secretary of State Rex Tillerson and Homeland Security Secretary John Kelly on Wednesday, as they met with Mexican officials to talk about the implementation of the Trump administration's more stringent immigration and deportation guidelines. An even colder response is probable as the administration advances President Trump's pledge to build a border wall for which he wants Mexico to pay.

The chill could be hemispheric if the wall becomes a barrier between better U.S.-Latin American relations. If so, it would be a major missed opportunity for a new administration already occupied with chronic crises in Asia, Africa and Europe.

This could and should be an era of newfound regional cohesion, especially since the so-called "pink tide" of leftist Latin American governments seems to be receding.

More conservative leaders are seated in Brasilia and Buenos Aires after incompetence and corruption corroded their predecessors' rules. In Quito, the leftist presidential candidate Lenin Moreno faces a runoff with more centrist Guillermo Lasso to decide Ecuador's election. And in Caracas, Venezuela's socialist President Nicolas Maduro — lacking the cash (and charisma) of predecessor Hugo Chávez — has driven his country into chaos if not the brink of collapse.

This shift isn't driven by ideology but rather a rejection of failed policies and a turn toward pragmatic approaches to governance, Michael Shifter, president of the Inter-American Dialogue, told attendees at a Global Minnesota event on Wednesday. Part of this pragmatism — urged on by the United States — is an embrace of free trade. And yet, Shifter said, in large part Trump based his campaign on an anti-trade and anti-immigration platform that is now embodied in the serious strains between the U.S. and Mexico.

Regardless of Trump's position on free-trade agreements, many Latin American countries will still pursue transnational trade pacts. If the U.S. balks, it may play to China's advantage.

"If the U.S. wants to pull back, China is very pleased to fill the void," Shifter said, adding that they won't do it for ideological but economic reasons.

While challenges abound, positive political developments do, too.

After decades of deadly strife between government forces and FARC guerrillas, peace seems a real possibility in Colombia. And renewed diplomatic relations between Washington and Havana have largely removed the Cuba excuse some Latin American leaders have used to distance their nations from the U.S.

These and other positive developments should be built upon, not squandered by unwise White House policies. It's not too late for the administration to correct its course, or for Congress to intervene on the nation's, and indeed the Western Hemisphere's, behalf.