A Flávio Bolsonaro victory in Brazil’s election could give Argentina’s president, Javier Milei, an ideological ally next door—but cost him his special standing with Donald Trump, according to an analysis published Saturday by iProfesional. The vote pits two South American partners seeking Washington’s favor against each other, with Brazil’s larger population and economy giving it a clear advantage.
The contest for Washington’s attention
“If Bolsonaro wins, the United States will give more room to Bolsonaro than to Milei,” an unnamed source in Argentina’s foreign ministry told political writer Mariano Obarrio. The source pointed to Brazil’s scale: “Brazil weighs more as a country and because of the size of its economy.”
Officials at the Casa Rosada, the presidential palace, told iProfesional: “They would love Bolsonaro to win, but ‘worry’ isn’t the word.” Their calculation concerns influence at the top. The report said Milei was wary of intervening directly in the campaign, though he hadn’t ruled out traveling to Brazil if Flávio Bolsonaro won the first round.
Brazil has about 213 million people, more than four times Argentina’s population, and Latin America’s largest economy. In a separate analysis, Argentine outlet TotalNews quoted Benjamin Gedan of the Stimson Center, a Washington think tank. Gedan, a former White House adviser on South America, called Flávio Bolsonaro “as MAGA as Milei” and said he was “equally committed” to becoming Washington’s main South American ally.
Security policy adds another dimension to the contest. Flávio Bolsonaro has promised that Brazil would join the Shield of the Americas, a U.S.-led security initiative Argentina already belongs to. The account describes political leaders competing for access and standing; it offers no grassroots response or mutual-aid effort to counter those decisions.
Diplomatic theater, material ties
Milei joined Flávio Bolsonaro’s campaign launch in São Paulo on 25 July. La Nación reported that Milei called Flávio a friend and Lula a “thief.” His relations with President Lula have collapsed. In August, Brazil downgraded its diplomatic representation in Buenos Aires, and neither ambassador had returned to post, according to La Nación.
Flávio Bolsonaro had also courted Argentina. In June, he promised Brazil would “return to being a brother to Argentina.” His economic coordinator, Daniella Marques, said his plan draws on Milei’s approach. Talk of brotherhood sits beside a rivalry over Washington’s attention—and a diplomatic freeze between neighboring governments.
The economic connection is harder to dismiss. Two-way trade between Argentina and Brazil reached US$31.2 billion in 2025, a 13-year high, according to the Rosario Board of Trade. Argentina exported US$12.8 billion in goods to Brazil and imported US$18.4 billion, leaving a deficit of about US$5.7 billion. Forbes Argentina reported that cars, car parts, wheat and fuel account for much of the trade. Both governments have reason to repair relations, whatever the election delivers.
The vote is not a guarantee
A Bolsonaro victory could end the diplomatic freeze. A Lula victory would leave Milei facing a neighbor he has repeatedly insulted. Brazil scheduled the election for Sunday, with polls due to close at 17:00 Brasília time, also 17:00 in Buenos Aires and 20:00 UTC. If no candidate won more than half of the valid votes, the top two would meet again on 25 October.
Buenos Aires’s concern reflects the judgment of unnamed officials, not a signal from Washington. Trump hadn’t endorsed Flávio Bolsonaro, Time reported, though he called Brazil’s vote very important. iProfesional described the possible double effect for Milei: a like-minded partner next door, but one from a much larger country sharing Trump’s attention. The leaders are counting votes, allies and economic weight. The people whose lives sit beneath those calculations don’t appear in the account.