The cost of public transportation for a family living in Rio or São Paulo is, proportionally, higher than in New York or Paris. Yet, the service delivered is humiliating. In 2009, security guards of a train company that services the Rio metropolitan area used whips on passengers during rush hour crowding. The mayor of Rio has proudly declared that during his tenure not a cent is being spent on subsidizing public transportation. Yet he was able to find $560 million of public money to spend on the renovation of the iconic Maracanã stadium to meet the requirements of next year’s FIFA World Cup.

At a time when federal, state and municipal taxes eat up 36 percent of Brazil’s gross domestic product without providing public services minimally compatible with what is expected from government, at least $13 billion is being poured into 12 soccer stadiums to host the World Cup. An additional $12 billion is being spent on projects to host the2016 Summer Olympics in Rio.

But delusionary modernism has its pitfalls. The same day the first protests started in São Paulo, the city’s mayor and the state’s governor happened to be in Paris trying to land yet another global mega event — the 2020 World’s Fair. A few days later, when the protesters were climbing atop the Congress building in Brasília, a landmark of Oscar Niemeyer’s architecture, the president of the House of Representatives was visiting Moscow.

The lavish lifestyle of high-ranking public servants (generous travel expenses, official cars with drivers, offensively large paychecks) has become a rallying point for the protests.

It is as if there are two Brazils. One is expected to shout — but only in stadiums. The other does as it pleases.

When Ms. Rousseff attended a Confederations Cup soccer match between Brazil and Japan last week, she was incensed when waiters started serving Champagne and caviar in the V.I.P. section. After she complained, popcorn soon materialized for the luminaries. Notwithstanding her protest, Ms. Rousseff was soundly booed by the rest of the crowd.

In today’s Brazil, there is too much caviar for the elite — and the people have noticed. That realization, along with outrage at widespread corruption, has helped the current outcry cross class, party and generational lines.

In 2005, the government of Luis Inácio Lula da Silva, then Brazil’s president, was caught in a vast cash-for-vote scandal. The plot, which became known as “mensalão,” because the bribe payments were made monthly, shattered expectations. Mr. da Silva’s government had been widely trusted to lead a fight against corruption. Suddenly, a former president of his Workers’ Party and his own chief of staff were caught up in a scandal.

Almost eight long years later, Brazil’s Supreme Court sentenced 25 of the accused. Their sentences ranged from 2 to 40 years in prison. But none are actually behind bars yet, and legal appeals could continue for another couple of years.

To grasp the significance of this, Americans need only contemplate their rage if the Watergate scandal had dragged on, enabling Richard M. Nixon to finish his second term, help elect a handpicked successor from his own party in 1976 and then watch all those indicted, tried and convicted walk free eight years later.

When the riot police in São Paulo fired rubber bullets and tear-gas bombs at protesters, they probably thought they were dealing with a couple of thousand worthless rioters. How could a national protest against bus-fare increases averaging less than 10 cents possibly be representative of modern Brazil, where people drive cars and, whenever possible, go shopping in Miami or New York?

But all who witnessed that very first act of police aggression know it was deliberate. It was gratuitous. And it was a colossal mistake.

In the face of growing protests, governors and mayors — who at first were intransigent — rushed to lower the transportation rates. Ms. Rousseff praised the shouting crowds, then conferred with Mr. da Silva and his spin doctors. Last week, in a much anticipated address to the nation, she declared that the voice of the streets was being heard and announced programs to promote better education and health care. On Monday, she took a more personal step, meeting with the leaders of the movement that triggered the protests. Her immediate aim is to survive the final week of the Confederations Cup without a major catastrophe in the streets.

As the protests have intensified, there have been cases of looting and vandalism. But the great majority of the protesters aren’t rioters, nor should the rioters be mistaken for protesters.

Indeed, it would be safe to assume that the percentage of violent troublemakers among the protesters is smaller than the number of thieves among the negotiators of government contracts.