What is happening in Brazil?
President Michel Temer is fighting to hold onto his job after a prominent business leader secretly recorded him in a conversation about buying off judges, prosecutors and other politicians as part of a plea bargain. It's the most explosive development to date in the long-running Lava Jato corruption investigation that has ensnared much of the political class.
The evidence against Mr. Temer seems damning. Will he resign?
He says he won't, and if he can scrape together a coalition of allies (or politicians who fear being pulled down with him if he goes) he might hold on until the end of his mandate in December, 2018.
Read more: Brazil seized by corruption allegations against President
What happens if he resigns?
Brazil's constitution says that in the event the president resigns in the second half of his or her mandate, he or she is replaced by the speaker of the lower house of Congress. The acting president has 30 days to hold an indirect election for a new president – a vote by the members of Congress to choose a new president. Some constitutional experts are suggesting that it is not necessary for this person to be a sitting Congress member: The candidate could be someone unelected. That, and other details of the election, could end up as the subject of Supreme Court cases, since this is untested ground for this constitution, adopted in 1988 after the end of the dictatorship.
But in the meantime, the lower house speaker would be acting president? Who is he?
Rodrigo Maia, 46, is serving his fifth mandate representing the Democratic Party and is a close ally of Mr. Temer's. He became the speaker of the lower house when the powerful politician Eduardo Cunha was forced out last year (he's now serving a 15-year sentence for corruption, and on the secret tapes, Mr. Temer allegedly orders that he continue to receive hush money in jail). Mr. Maia is under investigation in two different Lava Jato cases now before the Supreme Court – and if he is charged, he likely would not be able to hold the office: Last year the Supreme Court ruled that the then-chief of the senate could not be in the presidential line of succession because he is facing charges under Lava Jato, and this precedent would likely be applied to Mr. Maia, experts say.
So then what would happen?
Next in the line of succession is the current chief of the senate, Eunicio Oliveira – but he's also under investigation for corruption. If he should be charged, then Carmen Lucia Antunes Rocha, chief justice of the Supreme Court, would get the job.
Isn't there a way to force Mr. Temer out?
Yes. Congress can impeach him – a long process that will likely involve many Supreme Court appeals. The impeachment of his predecessor, Dilma Rousseff, took six months of formal proceedings. If Mr. Temer is impeached, the lower house speaker becomes president and has to hold an indirect election in 30 days. For this to happen, however, Mr. Maia has to accept an impeachment demand – and it's not clear that he will, given his close relationship with the embattled president.
The Supreme Court authorized a criminal investigation of Mr. Temer – could the courts remove him?
Yes: The Supreme Court can suspend Mr. Temer from office if he is under investigation for a crime such as obstruction of justice – but only with the authorization of the lower house. Then the process is the same as for impeachment.
Is there any other way for Mr. Temer to leave office?
Yes: There is another case, currently in front of the electoral court, which argues that because Mr. Temer was elected vice-president alongside Ms. Rousseff in an election that was won on "caixa dois" (illegal funds) in 2014, he cannot legally hold the office and must step down. The case is scheduled to be heard by the electoral court in the first week of June. Until the revelations of the secret tapes, it was seen as unlikely that the case would proceed to the point of a judgment before Mr. Temer's mandate ends – most of Brazil's powerful interests had an interest in maintaining stability. Now, though, it seems a distinct possibility that he might be forced out through this route, which spares his Congress colleagues having to impeach him. Then the lower house must hold an indirect election within 30 days.
Isn't there a way for Brazilians to elect a new president?
There is: a constitutional amendment. Two-thirds of Congress members would have to approve a law calling for a new direct election in 90 days. This is what demonstrators have been demanding at protests around the country. But analysts note that the Congress members, keen to hold onto their jobs, have little motivation to face enraged voters right now.
Who would likely win in a new election?
It would probably be a free-for-all, given the way that political careers have been going up in flames in recent weeks. Former president Luiz Inacio Lula da Silva has made clear he intends to run in the next election, whenever that is, and he tops the polls. But he is on trial for corruption at present, and if he is convicted, and that conviction is upheld on appeal, he would be barred from running. The current level of political chaos creates an opening for an "outsider" candidate, such as the environmentalist and evangelical Christian Marina Silva, or the far-right politician Jair Bolsonaro, an ex-soldier who speaks fondly of the military dictatorship but argues he is on the increasingly short list of those who have never been charged with corruption.
What is the impact of all this on Brazil?
The immediate impact is economic: In the 24 hours after the tapes were first reported, the Brazilian stock market and the currency each dropped by about 10 per cent. If Mr. Temer manages to remain in office, he will be badly weakened and will struggle to pass a key package of economic measures that he promised when he took office. They are deeply unpopular with the public, but viewed as key by investors and business owners. A lengthy impeachment threatens to erode any of the small gains made in the economic recovery and send the country firmly back into recession. At the same time, there is also upheaval in all of the entrenched political parties, and a possible opening for new actors. There is optimism about a new transparency in politics, an end of impunity and stronger state institutions (leaders on the level of Mr. Cunha have never gone to jail in the past). But weary Brazilians are also cynical, doubtful that all the turmoil will end with people's lives or the country improved.