Eduardo Cunha, then the speaker of Brazil's lower house of Congress, during a news conference in Brasilia on May 5, 2016. (Fernando Bizerra Jr./European Pressphoto Agency)

RIO DE JANEIRO — When Brazilian President Michel Temer was caught on tape in May seemingly greenlighting a bribe to silence a jailed politician, his fate became the talk of the nation. Less discussed was the man allegedly paid to stay silent: Eduardo Cunha.

Temer isn’t the only Brazilian politician who might want the widely reviled Cunha to keep his mouth shut. Few people have been at the center of Brazilian political life — and scandal — as long as Cunha, who is now serving 15 years in federal prison for corruption. If he starts spilling his secrets in return for a reduced sentence, political scholars say Cunha has so much dirt on so many politicians that virtually all of Brazil's political power brokers could be doomed.

“He is at the top of the political crime food chain,” says Michael Mohallem, a law professor at the Getulio Vargas Foundation in Rio de Janeiro.

It's not just Cunha's former colleagues who fear and loathe him. In an April survey by the Brazilian Ipsos Institute, Cunha was declared the most hated politician in Brazil, with 90 percent of Brazilians polled saying they disapproved of him. Fernando Haddad, the former mayor of São Paulo, calls him the “biggest gangster in the history of the country.”

Corruption allegations have dogged Cunha from nearly the first days of his public life. A trained economist, he began his political career in 1989 as treasurer for the Rio electoral committee of Fernando Collor de Mello, who won the presidency that year. Cunha was working under Collor when Collor was impeached for corruption in 1992; Cunha himself was implicated in the corruption scheme but never charged. He then allied himself with Rio’s governor at the time, Anthony Garotinho — who would later also be jailed on corruption charges.

Although he had been circling around government corruption scandals for years, Cunha's personal problems began in 1998, when he landed a spot at the helm of Rio's state housing authority. He was removed from office after just six months, accused of having awarded contracts without a bidding process and giving them to companies that did not exist.

Other politicians might have bowed out or kept a low profile, but Cunha had a lifeline: He ran an evangelical radio station, a powerful mouthpiece in a country with a growing conservative evangelical community. In 2001, his old friend Gov. Garotinho — in whose home Cunha sometimes recorded radio programs — stepped in and arranged a slot for him in the state assembly that would grant him immunity from the corruption charges.

In 2003, with Garotinho’s endorsement, Cunha was elected to Congress. He tapped into conservative values, authoring bills that appealed to socially conservative Brazilians, such as the proposed “National Day of Heterosexual Pride” and a law increasing the punishment for doctors assisting with abortions.

As Cunha climbed up Brazil's political ladder, he became the congressional leader of the Brazilian Democratic Movement Party, or PMDB, the current ruling party in Brazil. He became speaker of the lower house in 2015, and on August 31, 2016, he was the man in charge of one of the most important political events in Brazil's history: the impeachment of President Dilma Rousseff.

Cunha is viewed as the maestro of the impeachment, the man whom many Brazilians say helped broker the secret deals that got 367 members of Congress from various political parties to vote for Rousseff's ouster.

Cunha's role presiding over the impeachment on live television turned him into a villain for many of Brazil's leftists, who saw the impeachment as a coup. But he had also lost his already-limited support from the right as well. Months earlier, the Supreme Court determined that he should be investigated for demanding $5 million worth of bribes related to contracts between Samsung and Petrobras, Brazil's partially state-owned energy giant.

Just 12 days after overseeing Rousseff’s impeachment for fiscal irregularities, Cunha himself was removed from office for perjury, corruption and, among other things, lying about his foreign bank accounts.

His removal stripped him of his parliamentary immunity, and Cunha was jailed despite his televised protestations of innocence and explanations of why his wife had a foreign bank account linked to extravagant credit card purchases. His 15-year sentence is one of the most severe punishments a Brazilian politician has ever received.

For now, Cunha has remained quiet. In mid-August, prosecutors rejected a proposed plea bargain with Cunha, saying his testimony was too inconsistent. On the surface, it looked like Cunha’s secrets might stay locked up with him.

But he may simply be playing a longer game. A new attorney general will take over Sept. 18, one who might be willing to cut a more favorable deal. Some Brazilian media outlets speculate that Cunha is intentionally sabotaging his plea bargain so that he can deal instead with the incoming attorney general.

However, other high-profile plea bargains have been criticized for being too favorable to the incriminated. That led Mohallem to note that negotiating with the notorious Cunha could be a risky prospect for Brazilian prosecutors: “The idea of dealing favorably with Cunha would create a really bad impression. People won’t see this as just.”

If Cunha does end up cutting a deal, it would be especially bad news for President Temer. After surviving a congressional vote last month that would have sent him to trial on corruption charges, Temer looked to have stabilized his presidency. “At this moment the game is in his favor,” Mohallem said.

Cunha could change all that, said Ricardo Ismael, a political-science professor at the Pontifical Catholic University in Rio de Janeiro: “He could pull out the last card he has up his sleeve, throw it on the table, and end Temer.” For now, Temer — and many other Brazilian politicians — can only wait to see which hand Cunha plays.

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