But, this being Brazil, that doesn’t mean Temer is a stodgy technocrat taking the helm.
A legal scholar and sometime poet, Temer, 75, is famous for his dapper suits, slicked-back silver hair and wife -- who will turn 33 on Monday -- who was only a toddler when Brazilian democracy returned in 1985 after two decades of military rule.
He is the author of "Anonymous Intimacy," a book of sensual verses inspired by his wife, Marcela, who was a 20-year-old aspiring beauty queen when she became Temer's third wife in 2003.
Temer has assumed Brazil’s presidency on an interim basis, but given the overwhelming margin by which Rousseff lost Thursday's vote, there appears to be a growing likelihood he will serve out the rest of her term through 2018.
The son of Christian Lebanese immigrants, Temer has signaled he will take Brazil and its ailing economy in a more free-market direction. His popularity ratings have registered even lower than Rousseff’s in recent polls, and though he, too, has been named in Brazil's corruption investigations, those who know him well say he has the political skills to quickly win over a skeptical public.
“I have never since [seen] someone as prepared for this emotionally as Michel Temer,” said Jacob Goldberg, one of Brazil’s most celebrated psychoanalysts, whose clients have included many politicians, artists, and star athletes. He called Temer “a cordial man, a man of dialogue” and “not a man of confrontation.”
“He is someone prepared for crisis. He is a man prepared for stress,” said Goldberg in an interview.
“As a psychoanalyst, I have seen very few people as prepared as he is,” he said, though he declined to confirm whether Temer has been his patient, citing confidentiality. But they have known each other for decades and maintain a close relationship.
Added Goldberg: “Brazil will discover a very charismatic politician.”
This has not always been Temer's reputation. He is sometimes mocked as "The Butler" because he is said to resemble a character in a campy horror movie and is the kind of restrained figure who seems to know much but say little in public.
Analysts say he will have to quickly overcome public distrust and doubts about his path to the presidency. He is vilified by Brazilian leftists who see him as an unctuous, shadowy figure. Tens of thousands of Facebook users defaced Temer's page Thursday with tiny vomit emoticons.
Temer ran on Rousseff's ticket in 2010 and again in 2014 when his centrist PMDB party was allied with hers, but the two were never close. In a widely-circulated letter that surfaced last year, he complained to Rousseff that she didn't trust him and relegated him to a do-nothing role.
Their relationship soured further last month when an audio tape surfaced of Temer rehearsing a speech to the country as if he had already assumed the presidency. Rousseff called him "a traitor" who was conspiring to steal her job.
In the meantime, with Rousseff fighting for survival, he began conspicuously assembling his cabinet, building support among the country's many political parties by dangling ministerial jobs in the presidential palace.
Brazil’s main stock exchange was up slightly as he took power, with Brazil’s currency, the real, strengthening against the dollar. Temer has promised to overhaul Brazil's tax codes, push much-needed pension reform and implement other business-friendly policies to try to stimulate growth and shore up a tanking economy projected to shrink 3.8 percent this year.
With millions out of work, Temer is not planning to cut a key welfare program called "Family Allowance," which provides cash payments to keep many of Brazil's poorest afloat, according to aides.
Joao Pedro Ribeiro, an economist at Nomura Securities in New York specializing in Brazil, said Temer will zero in on the country's economy in the interest of building the consensus he'll need to get legislation through Brazil's congress.
“On the growth front, things are slow and there is not much he can do immediately," said Ribeiro. "But there are things that can be done that have a long-term benefit for the economy, and markets will respond to that."
In addition to doubts about the legitimacy of his path to power, Temer also faces the risk that accusations of wrongdoing could force him out.
Temer has been accused by a government witness in the sprawling investigation of corruption at the state oil giant Petrobras, the scandal that has swept up dozens of lawmakers and fueled anger at Rousseff's government and Brazil's entire political class.
Temer's name was not included on a list of powerful politicians that Brazil's top prosecutor last week asked the Supreme Court to add to the list of those being investigated. But the prosecutor said that Temer's party, the PMDB, was deeply involved in the graft during the period when he was its president.
Temer was fined this year after an unrelated investigation by a regional electoral court found him in violation of campaign finance laws, meaning he could be barred from running for office for eight years.
He has already promised he will not be a candidate for president in 2018.