Flip Gordon was down on the mat.

He was in the arena as a lucha libre wrestler in Mexico, taking a pounding in a recent tag-team match.

What was most remarkable, while bodies flew around the ring and the muscular Mr. Gordon struggled to get back on his feet, was the brief chant that rang in the air as he battled that night: “Gringo! Gringo! Gringo!”

When Mr. Gordon, whose real name is Travis Gordon Lopes Jr., flings himself into the ring, his presence raises some potentially uncomfortable questions.

What happens when an American, and a former U.S. soldier at that, competes in a profoundly Mexican form of entertainment — known for colorful masks, outlandish outfits and high-flying acts — while wearing camo, boots and dog tags? Can a fan base bound up in Mexican nationalism, spurred by President Trump’s threats of military action in their country, embrace and cheer for a man dressed like G.I. Joe?

And what happens to a wrestler who has become an immigrant in Mexico at a moment of intense strain between his country of origin and his new home?

Regardless of their costume, foreigners in the world of lucha libre often wrestle as a “rudo,” a rule-bending bad guy who uses brute force. But in a twist, and despite his American soldier’s garb, Mr. Gordon actually wrestles as a “técnico,” a good guy, because of his more acrobatic, finessed style and how he won over crowds.