BRASÍLIA—Luiz Inácio Lula da Silva, the 77-year-old standard-bearer of Latin America’s left, returned to power Sunday, 12 years after his last stint as president. This time around he faces some of his toughest challenges yet, from uniting a bitterly divided nation to halting the destruction of the world’s biggest rainforest and boosting the incomes of millions of desperately poor families.
Thousands of supporters, many singing and waving the crimson flag of the Workers’ Party, joined dignitaries from across the Americas in the capital for the inauguration and a festival of open-air concerts to celebrate the return of Mr. da Silva, known popularly as Lula.