When Andy Ruiz Jr claimed his heavyweight title belt in Madison Square Garden last weekend it was the Mexican flag behind him, the flag of the country not where he was born but where his immigrant parents were from. “I’m the first Mexican heavyweight champion of the world,” he said after knocking out American star Anthony Joshua.

“Everyone who thinks I’m not Mexican simply because I was born in the United States is wrong,” Ruiz told ESPN. “My mom and dad are from Mexicali, and I feel more Mexican than others who were born in Mexico because I fought for my race and for Mexico.”

The border region where Ruiz is from has long been known for being fiercely bi-cultural. Families in Mexico cross the border to go to school, work and shop. Families in the US cross the border to visit relatives, go to the dentist and shop.

But with the arrival of president Donald Trump, tensions between the two countries have reached a new high. Trump made a war of words with Mexico the centerpiece of his presidential campaign and has lately been threatening across-the-board tariffs on all Mexican goods if the government of Mexico doesn’t do more to stop migration to the United States.

By proudly claiming a Mexican identity over an American one, Ruiz jumped into the center of a national political controversy.

While Ruiz is the first Mexican heavyweight champion, he is not the first bicultural boxer to rise to prominence during a time of political tension between the two neighboring countries.

Almost a century ago, a Mexican-American boxer called Bert Colima found himself in a similar situation.

Epifanio Romero was known to everyone by his nickname, a conjunction of ‘Bert’ because as a child he liked to sing like birds (Bert is derived from the word ‘bird’) and ‘Colima’ for the Mexican state where his grandmother was from. He was born in Whittier, California in 1902.

Colima was a well-known fighter in the California area, popular among Mexicans in Los Angeles for expressing his Mexican roots through his name change, said Servando Ortoll, a sociologist and historian who wrote a biography about the boxer called “Whittier lightning.”

“Colima was not known in Mexico. He was born in the United States and like Andy Ruiz emerging in similar contexts ” said Ortoll in a telephone interview.

Colima came of age as a boxer in the 1920s during a difficult period in Mexican-American relations.

Mexico was emerging from its decade-long revolution and the two governments were locked in a battle over unpaid debts Mexico owed to US investors to recoup damages from the war. The US ambassador to Mexico, James R Sheffield, expressed racist views about Mexicans, calling them “barbarians who needed to be taken over and civilized by Sons of Mother Yale” and cataloguing the Mexican cabinet members by how “white blooded” they were.

Mexico’s president Plutarco Elías Calles made a political calculation to counter all of the hateful rhetoric coming from the United States. He saw Colima as an emblem of common ground between the two countries, knowing that he was a popular fighter in California who also overtly claimed his Mexican heritage, said Ortoll. Calles’ government invited Colima to his first fight in Mexico City in March 1926 against the fighter Arthur Schaekels from Belgium. That fight was followed up by four more around the country in as many months.

“The government of Calles chose him to entertain people in the middle of the turmoil in the country at that time” said Ortoll. “They could have chosen other fighters that were around at that time, but they chose the one who had adopted a Mexican state for a last name.”

Colima was not a world champion but he is known as the first widely recognized Mexican-American boxer. After the fights in Mexico, he was welcomed as a native son.

History repeats itself. Immediately after Ruiz won his championship, he received a call from the recently elected [resident of Mexico Andrés Manuel López Obrador inviting him for a state visit.

Ruiz’s Mexican pride – he has boxed for Mexico in a pre-Olympic tournament and he started his amateur career in Mexico – has ignited controversy on social media. Critics say he is not Mexican but American because of where he was born.

But Mexicans have embraced him as one of their own. César González, the editor of the Mexican boxing website Izquierdazo said what matters is how Ruiz fights, and he fights like a Mexican.

“Andy Ruiz embodies the essence of Mexican boxing. The people want to see someone baptized in blood, who gets cut, falls down but then gets up and triumphs. The people want drama. They want something epic. And that’s what he did.”