Less than 24 hours after losing Brazil’s presidential election, Flávio Bolsonaro appeared to vanish into a convoy of four dark cars. After pulling away from his home in Brasília on Monday evening, the vehicles split in different directions, leaving journalists and authorities scrambling to determine which one carried Bolsonaro. By the next afternoon, the former presidential candidate’s allies were telling reporters he had already reached Florida.

As Brazilian and international outlets reported that Bolsonaro had left the country, he was still in Brazil, while a private jet waited for him across the border in Argentina. At 12:21 a.m. Wednesday, the Gulfstream G400 took off from Puerto Iguazú and whisked him to Ecuador and then Miami, where his entry was facilitated by Trump allies his family spent years cultivating. The getaway—which relied heavily on deception and decoys—sparked a global guessing game that left even some of Bolsonaro’s closest allies in Washington and Brazil in the dark about his whereabouts.

After Bolsonaro stepped off the plane in Miami on Wednesday morning wearing a navy polo shirt and a backpack, uniformed officers used umbrellas to shield him and his family from cameras. Their arrival followed an extraordinary effort by a small circle of influential Trump allies, senior U.S. officials and Argentine President Javier Milei to help him fly to the U.S. and secure entry, despite a Brazilian court order barring Bolsonaro from leaving the country.

Referring to himself as the “leader of Brazil,” Bolsonaro thanked President Trump for welcoming him to a “land of freedoms” and Milei for his “courage” and “sense of justice” in a statement from Miami Wednesday.

After Trump personally approved admitting Bolsonaro and his family to the U.S. on Tuesday, Secretary of State Marco Rubio moved to issue them visas, according to people familiar with the arrangements.

But the family entered the country under humanitarian parole, which allows them to remain for one year, the people said. The operation to whisk Bolsonaro out of Brazil to the U.S. took shape on Monday, as allies grew concerned that he could face arrest. Although the criminal investigations into Bolsonaro predated the election, the Supreme Court order barring him from leaving Brazil and requiring him to surrender his passports came shortly after his defeat and fueled accusations that President Luiz Inácio Lula da Silva was determined to punish his political rival.

Working with Flávio Bolsonaro’s well-connected younger brother Eduardo, a small group including Trump adviser Jason Miller secured a charter jet to take him from Argentina to Florida. The Trump administration’s decision to provide refuge to Bolsonaro marks the culmination of the family’s yearslong lobbying campaign to enlist the U.S. president and his inner circle in its legal and political battles at home. The personal alliance between the two most powerful political families in the hemisphere has reshaped relations between the U.S. and Brazil.

Last year, Trump imposed steep tariffs on the country citing its treatment of Bolsonaro and sanctioned the same Supreme Court justice who barred Bolsonaro from leaving Brazil. President Luiz Inácio Lula da Silva won an unprecedented fourth term in Brazil. WSJ’s Samantha Pearson explains what Lula’s victory means for President Trump and his right-wing allies in Latin America. Photo: Paulo Lopes/Xinhua/ZUMA PressNow, what began as a domestic political and legal battle in Brazil is becoming a test of how far Trump is willing to wield American power on behalf of a foreign political dynasty—with potentially far-reaching consequences for the second-largest democracy in the Americas.

Bolsonaro intends to set up a political operation in exile from the U.S., people involved in discussions with him said. But with the U.S. midterm elections days away, the White House has given little indication that it intends to go beyond offering Bolsonaro refuge or that Trump will expend political capital challenging da Silva’s re-election victory, despite pressure from allies in Washington, according to two people involved in the discussions. Trump declined to comment when reporters asked him about Bolsonaro declaring himself the rightful president of Brazil.

“I thought they were treated very unfairly,” he said on Wednesday about the Bolsonaros, who he described as “very fine people” earlier in the day. “But I won’t get involved—it was a very strange election, that’s for sure.”

Da Silva’s victory in Sunday’s runoff election against Bolsonaro was recognized by more than 50 countries, including Latin American leaders across the political spectrum. He defeated Bolsonaro by more than 4.4 million votes, a margin that international observers said left no doubt about the integrity of the country’s electoral data. Trump, however, has so far refused to formally recognize da Silva’s victory, instead suggesting without evidence that the results might have been rigged. The long way to MiamiOn Tuesday, the conservative senator and his family headed to the Argentine border, hundreds of miles away.

That night, at 10:50 p.m. local time, Bolsonaro, his wife and their two daughters crossed the Tancredo Neves International Bridge into Puerto Iguazú, Argentina, near where the borders of Brazil, Argentina and Paraguay meet, according to Argentine authorities.

After crossing the border, Bolsonaro’s vehicle was escorted by Argentina’s airport security police to the immigration checkpoint at Iguazú Falls International Airport. The operation was being monitored from Puerto Iguazú by Santiago Caputo, a top Milei aide, according to a former Argentine intelligence chief.

Caputo was in direct contact with Eduardo Bolsonaro to coordinate, according to a person involved in the operation. Milei is a close ally of both the Trump administration and the Bolsonaro family. In July, he attended a campaign rally for Flávio Bolsonaro in Brazil, calling da Silva a “thief,” which prompted Brazil to recall its ambassador to Argentina.

At the airport, a private jet owned by Baires Fly, a charter airline, was waiting for the Bolsonaro family after the plane arrived from Buenos Aires a day earlier, according to flight-tracking data. At 11:30 p.m., Bolsonaro boarded the Gulfstream, flight LV-JQW, which flew to Guayaquil, Ecuador, to refuel on its way to the U.S. An Argentine flight manifest reviewed by The Wall Street Journal lists Bolsonaro, traveling on an Italian passport, alongside his wife and two daughters. The flight then departed shortly after midnight, with two pilots on board and a flight attendant.

The jet landed at the Miami-Opa Locka Executive Airport at around 9:30 Wednesday morning. As they left the airport, Bolsonaro and his family were rushed into a waiting SUV.

Bolsonaro’s arrival in the U.S. follows in his father’s footsteps. In December 2022, Jair Bolsonaro landed at Orlando International Airport after losing an election to da Silva and refusing to concede. The elder Bolsonaro stayed for around three months, living at the home of a friend before returning to Brazil. He was later convicted of plotting a coup to stay in power, which culminated in an uprising in Brasília that drew comparisons to the Capitol riots of January 2021. Shared grievancesThe Supreme Court order preventing Bolsonaro from leaving the country gave fresh ammunition to the Bolsonaro family’s longstanding allegations of political persecution.

With help from influential allies, including Miller and former Trump strategist Steve Bannon, the Bolsonaros have cast their legal fights back home into a broader campaign of political persecution that has resonated with Trump.

Spearheaded by Eduardo Bolsonaro, the campaign to cultivate Trump and his inner circle has stretched from Mar-a-Lago dinners and CPAC conferences to White House meetings. At Trump’s inauguration last year, Eduardo embraced Donald Trump Jr. after attending a dinner hosted by Vice President JD Vance. Bannon, the former Trump strategist who previously advised the Bolsonaro family, argued that the left’s treatment of the Bolsonaros offered a warning to U.S. conservatives.

“People in the United States who think politics are going to get easier haven’t seen anything,” he said. “This is only going to get nastier, more partisan and more aggressive.”Trump has similarly drawn parallels between Brazil’s elections and the prosecution of the Bolsonaros as part of the same struggle against a leftist “witch hunt.”At a campaign rally in Texas on Tuesday, he accused Democrats of being “the greatest cheaters of elections in history” before adding, “although Brazil is doing a pretty good job also, aren’t they?”

Write to Vera Bergengruen at vera.bergengruen@wsj.com, Samantha Pearson at samantha.pearson@wsj.com, Ryan Dubé at ryan.dube@wsj.com and Philip Wegmann at philip.wegmann@wsj.com