The homecoming on Thursday of Brazil’s former president, Jair Bolsonaro, has the potential to threaten the hold on power of President da Silva and to further deepen the country’s political crisis.

Mr. Bolsonaro returned to Brazil after a self-imposed exile in Florida following his defeat in last year’s presidential elections. Hundreds of supporters wearing yellow and green shirts camped at Brasilia International Airport to welcome the former president, who landed around 6:30 in the morning local time. 

Despite the former president’s legal woes, his return is bound to present a major challenge to Mr. da Silva’s already strained government. Mr. Bolsonaro is preparing a strategy “to demonstrate that he is still Lula’s main antagonist,” a professor of international relations at the Federal University of San Pablo, Regiane Nitsch Bressan, tells the Sun.  

Mr. Bolsonaro is using the press and social media platforms to counter Mr. da Silva’s government “in an attempt to divert from the accusations against him,” Ms. Nitsch Bressan says.

Before departing Orlando on Wednesday, Mr. Bolsonaro taunted Mr. da Silva, telling CNN Brazil that he does not plan to lead a political opposition against the president. “It is not necessary to create an opposition against this government,” Mr. Bolsonaro said, “it is creating its own opposition itself.”

Yet Mr. Bolsonaro expressed his intention to resume his political career and tour Brazil’s states “once or twice a month” as next year’s municipal elections approach.

Allies in the Liberal Party encouraged Mr. Bolsonaro’s supporters to show “solid support” at Brasilia. Fearing a loss of control, the federal police created a security system for Mr. Bolsonaro that separated him from his crowd, according to the Brazilian newspaper O Globo.

Mr. Bolsonaro announced his return to Brazil a week ago, on the eve of Mr. da Silva’s trip to Beijing, where he was scheduled to meet President Xi. The trip was postponed Saturday when Mr. da Silva was hospitalized with what was described as “bacterial and viral bronchopneumonia due to influenza.” 

In March, Mr. Bolsonaro joined President Trump’s Conservative Political Action Conference at Washington, where he made clear that his political mission is not over. He said he intended to win back the country from the left-wing government, and accused Mr. da Silva of corruption and ties to communism.

Mr. Bolsonaro’s Liberal Party dominates Congress, holding 99 of the chamber of deputies’ 513 seats, which is the largest majority for one party since 1998. Mr. da Silva’s left wing Workers Party commands 80 seats, so the president is forced to coalesce with a bloc of congressional centrists, known as the Centrão, to get any initiative approved.

The Centrão encompasses several political parties and has 220 seats in the chamber, or 48 percent of the total, and many of its deputies often disagree with Mr. da Silva. In many cases they would rather join forces with the Liberal Party, which has its own partners in the chamber. As a result, Mr. Bolsonaro’s party and its allies control the legislative process, which could ease the former president’s attempt at recapturing the presidency.  

Next week, Mr. Bolsonaro will mark his return to politics by assuming honorary leadership of the Liberal Party. His wife, Michelle, is launching a political career as well, and is seen by some as a potential future presidential candidate. 

Next year’s municipal elections could become a platform for the Bolsonaros to launch a campaign for the 2026 presidential election. Already amassing significant support at Brazil’s largest cities, Rio de Janeiro and Minas Gerais, Mr. Bolsonaro is expected to also back the Liberal Party’s mayoral candidates who, if elected, would in turn support his presidential bid, according to Brazilian press reports.

Mr. Bolsonaro’s political aspirations, though, could be cut short by a series of investigations taking place in Brazil. In addition to his involvement in the January 8 attacks on Brazil’s democratic institutions, Mr. Bolsonaro is the subject of more than a dozen criminal investigations, mostly regarding alleged illegal activities during his 2022 presidential campaign.

One such probe involves three boxes of expensive jewelry that Saudi Arabia’s royal family gave Mr. Bolsonaro in 2021. Instead of handing over the jewelry, worth up to $3.2 million, to the Presidential Palace, he allegedly kept it for himself. The federal police plans to call Mr. Bolsonaro to testify next Wednesday. 

If Mr. Bolsonaro is found guilty in any of these cases, he could lose his political rights and aspirations to return to the Planalto Presidential Palace in 2026.