The new year marked the beginning of a new era for Latin America’s largest country. Jair Bolsonaro, the far-right winner of Brazil’s presidential election, assumed office amid a remarkable swirl of contrasting expectations. While the former army captain’s incendiary declarations during the election campaign last fall sparked fears among millions of Brazilians and others abroad, a less noticed phenomenon took shape in the weeks leading up to his inauguration on Jan. 1: Brazilians, by large majorities, are optimistic about his tenure.

In two surveys last month, Brazilian pollsters found that a stunning 75 percent of respondents approved of Bolsonaro, and two-thirds expected the new administration to bring about a turnaround in Brazil’s economic fortunes. That is notable, and a bit of a head-scratcher, considering that for years the most popular politician in the country has been former President Luiz Inacio Lula da Silva, a leftist leader who made his name as a union organizer and a campaigner for social justice, essentially embracing policies that Bolsonaro diametrically opposes. ...