BRASILIA >> They are at once ubiquitous and invisible here, the street cleaners, landscapers, hotel maids and traffic police who make sure Brazil’s meticulously designed capital stays true to the national flag’s slogan of “order and progress.”

But as President Dilma Rousseff stands on the precipice of impeachment, it is hard to find much support here among the working-class voters who were once bedrock supporters of the Workers’ Party, the left-wing group that stood up to the nation’s military rulers a generation ago and later swept to power by promising a more just society.

“We had such high hopes for Dilma, but her government turned out to be just like the others — corrupt as criminals,” Valdenor Soares da Silva, 56, an ice cream vendor outside the National Congress, said Saturday. “Everyone I know feels the same way.”

Rousseff’s predecessor and political patron, Luiz Inacio Lula da Silva, enjoyed unprecedented popularity during his eight years in office, buoyed by generous social welfare benefits and frothy economic growth that helped move millions of impoverished Brazilians into the middle class.

Rousseff also enjoyed widespread support during her early years in office, but a slumping economy and a corruption scandal have ravaged her popularity. According to a recent poll by Datafolha, a research institute, Rousseff’s approval among the poorest Brazilians has dropped to 16 percent, down from 50 percent in December 2014. Among working-class Brazilians with a basic education, the numbers were similar: Support sagged to 18 percent from 54 percent during the same period.

Such figures reflect the disillusionment sweeping through a constituency that once helped propel the Workers’ Party.

“Everything has gotten worse — job opportunities, health care and crime,” said Helen Brandao, who was selling sandwiches, candy and bottled water from a food truck Saturday outside the Chamber of Deputies, the body that will vote Sunday on whether to begin impeachment proceedings.

Once firmly in the middle class, Brandao, 30, said she turned to street hawking six months ago after losing her job as a receptionist at a home repair company, which went bankrupt. A mother of three young children, she earns about $340 a month, nearly a quarter of her previous income, and said she had lost her dental insurance and cut back on family vacations.

“It’s gotten so bad, there are no doctors in the hospitals,” Brandao said. “A few years ago, no one imagined life would get so hard.”

Once a supporter of the Workers’ Party, she said it was time for Rousseff to go. “I’m for impeachment,” she said.

Across the street, Erisvaldo Rodrigues Marques, 43, has spent the last two decades polishing the shoes of politicians who stream in and out of the building. He credits a magnanimous politician with giving him the prime spot, and over the years Marques was able to buy a house in Planaltina, a 40-minute bus ride from the capital.

“I used to have four or five people waiting to have their shoes shined,” he said.

Marques, often idle now, blames Rousseff. “I favor the impeachment, only to see if something changes,” he said. “We want a new country.”

From his perch at a reception desk inside the Congress building’s entrance hall, Francisco Raimundo Rodrigues has seen it all: naked corruption, political betrayals and protesters who forced their way through the front doors, among them landless petitioners who once crashed a vehicle into the lobby.

“I could write many books, but I can’t say anything until after I retire,” he said.

But Rodrigues, 59, said the current government had been among the worst of his 30 years as a civil servant. “Dilma said she supported the poor, but it was just an illusion,” he said. His main complaint: Members of the Workers’ Party, he said, repeatedly rejected pay increases for people like himself.

He said he supported impeaching Rousseff, but acknowledged that a new government might not be any better. “But we have to try something new,” he said, adding a feel-good slogan popularized by the national soccer team. “Brazilians never give up.”

© 2016 The New York Times Company