Demonstrators join a rally in favor of Brazilian President Dilma Rousseff's government in Sao Paulo on March 24. (EPA/Ricardo Nogueira) (Ricardo Nogueira/EPA)

The biggest party in President Dilma Rousseff’s governing coalition jumped ship Tuesday, increasing the chances that the leader of Latin America’s biggest country will be impeached.

Rousseff faces the possibility of impeachment over allegations of fiscal irregularities in her government’s accounting. But she is also struggling with a huge corruption scandal and an economy in recession, and her popularity has plummeted.

The departure of the Brazilian Democratic Movement Party, which was expected, made it more likely that some of the other 11 parties that normally support Rousseff’s party could abandon her, too. Under Brazil’s presidential system, Rousseff would still remain in office for the moment, even though her Workers’ Party has only 58 of the 513 seats in the National Congress. But it may be difficult for her to muster enough votes to stave off her removal by the legislature.

“It reinforces the odds that impeachment will occur,” said Christopher Garman, managing director and Brazil analyst at the consulting firm Eurasia Group.

“We’re at the tipping point,” he said.

Brazilians have been transfixed as an enormous investigation into corruption at state-run oil company Petrobras has led to the jailing of politicians from Rousseff’s Workers’ Party and its allies as well as executives from important companies. Rousseff has not been charged in that probe, known as Operation Car Wash, although she was chairman of the board at Petrobras from 2003 to 2010. Contracting companies allegedly paid billions of dollars in bribes to Petrobras executives, middlemen and politicians to secure valuable contracts during and after that period.

While smaller parties in Brazil’s Congress shift alliances from time to time, it is rare for a major player such as the Democratic Movement Party, known as the PMDB, to break ranks. PMDB Senator Romero Jucá called the meeting that reached Tuesday's decision “historic.”

As part of the party’s break with Rousseff, six ministers will leave her cabinet, and about 600 members of the PMDB will quit government jobs at the state and federal level, according to party officials.

“All the indications are that the Brazilian people want change. They want change because the economic situation is very bad,” said Wellington Moreira Franco, a former minister of aviation from the PMDB who served under Rousseff.

A Brazilian congressional commission has begun considering Rousseff’s impeachment. If two thirds of the lower house votes to accept the process, Rousseff will be suspended for a maximum of 180 days while the Senate decides on her case. The lower house vote could happen as soon as next month.

If Rousseff is suspended, Vice President Michel Temer, a member of the PMDB, would take over as interim president. He will remain as vice president even though his party has withdrawn its support from the president.

While Rousseff has not been accused of any crime in Operation Car Wash, she has been damaged by testimony that she attempted to influence the investigation. She has also been criticized for her decision to approve the financially disastrous purchase of a Texas oil refinery by Petrobras when she was head of its board.

On March 13, more than 3 million Brazilians joined demonstrations calling for her impeachment and for the jailing of Luiz Inácio Lula da Silva, or Lula, her predecessor and the co-founder of her leftist Workers’ Party. Days later, hundreds of thousands demonstrated in support of the government and against what the president and Lula say is an attempted institutional coup.

On March 9, charges were filed against Lula in relation to properties that he allegedly controlled that were renovated by companies involved in the Car Wash scheme.

Rousseff, elected to a second term in 2014, succeeded the then-highly popular Lula, a former union leader who won fame for social policies that lifted more than 30 million Brazilians out of poverty.

The PMDB has also been linked to the Petrobras scandal. Eduardo Cunha, a member of the party and speaker of Brazil’s Chamber of Deputies, faces charges at Brazil’s Supreme Court of corruption and money laundering in relation to the investigation into the oil company’s dealings.

In recent polls by the Datafolha polling institute, 68 percent of Brazilians supported the impeachment of Rousseff and 76 percent said Cunha should resign.

Some 60 percent of members of the Brazilian Congress face court processes for offenses such as corruption, money laundering, electoral irregularities and misconduct in public office, according to Transparencia Brasil, a nongovernmental monitoring group in Sao Paulo.

And the more Operation Car Wash uncovers, the less Brazilians are inclined to trust anybody in Congress.

“No one group is better than the other,” said Bruno de Souza, 35, a Rio hairdresser. “All those who enter there want to get rich.”

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