RIO DE JANEIRO — Thousands of protesters took to the streets again across Brazil on Sunday to demand the ouster of President Dilma Rousseff, who faces impeachment proceedings that could drag on for months while her government struggles to lift the economy from its most severe crisis in decades.

The protests appeared to be smaller than earlier demonstrations calling for her ouster, perhaps offering some comfort to the beleaguered president. Even so, the vitriol expressed by many protesters, including calls by some for the armed forces to remove Ms. Rousseff, reflect the increasing polarization in the country that is making it harder for her to govern.

“We need a military coup,” said Sonia Alves Brito, 67, a teacher at a day care center who joined a march through the seaside district of Copacabana in Rio de Janeiro. “Brazil was better off during the military dictatorship.”

That protesters are publicly voicing such views, which would have been taboo a year ago, illustrates how fed up many Brazilians are with the graft scandals and economic mismanagement that have characterized Ms. Rousseff’s leftist government, even to the point of feeling nostalgic for the period of military rule from 1964 to 1985, when the economy was mangled by hyperinflation and human rights abuses were widespread.