– “It’s not about the 50 cents” reads a scrawl on a shop shutter on Avenida Faria Lima, one of São Paulo’s main thoroughfares. Next door, the message is more blunt: “Screw the police.”

Six months after a small demonstration against a 50-cent rise in bus fares blew up into the biggest street protests Brazil had seen in a generation, few visible signs remain of the wider anger they revealed — about corruption, poor public services and rising living costs. Recent attempts to organize a reprise have attracted only a few hundred marchers. Support for the president, Dilma Rousseff of the Workers’ Party, which plummeted after June’s protests, has rebounded. A poll in November of voting intentions in next October’s elections gave her 47 percent, against 30 percent for her two likeliest adversaries combined.

Even so, the race is difficult to call. The same poll found that two-thirds of voters want Brazil’s next president to make sweeping, if unspecified, policy changes. That suggests the spirit of June is still alive — and that some of Rousseff’s support could melt away if a strong alternative emerges. Political analysts say that many Brazilians’ voting strategy is to plump for the perceived front-runner, whoever that may be, meaning that a challenger who manages to advance in the polls could quickly take a commanding lead.

Neither of Rousseff’s probable adversaries is yet campaigning in earnest. Aécio Neves’s Party of Brazilian Social Democracy has been hit by evidence of bribery and overbilling on public contracts in its heartland state of São Paulo. Eduardo Campos, the governor of the state of Pernambuco, is hammering out a program with his likely running mate, Marina Silva, an environmentalist who joined his party after missing a deadline to set up her own.

The economy offers a line of attack for both candidates. Since Rousseff took office in 2011, growth has been ­anemic. Unemployment is low and, until recently, incomes had risen faster than inflation. But job creation and wage growth are now cooling, while prices are still going up. The public finances have deteriorated — and will not be repaired in an election year.

A spoof calendar circulating on social-networking sites paints 2014 as another lost year for growth, with a late Carnival extending the summer break (in the Southern Hemisphere) from Christmas to March and a three-month shutdown around the football World Cup, which Brazil is hosting. It shows May devoted to preparations, June to the tournament and July to celebration — or, just as conceivably, mourning. Extra spending on beer, Nike soccer shirts and new televisions will barely offset the closure of schools and government offices on match days in order to get locals off host cities’ congested roads and allow fans to get to games.

Anarchist gangs may cause havoc

The World Cup brings other risks for the incumbent. Last June’s marches coincided with the Confederations Cup, a dress rehearsal for this year’s tournament. The timing added fuel to protesters’ rage by highlighting the contrast between pricey new stadiums and shoddy public infrastructure, and gave them a chance to air grievances with the world watching. Brazilians’ passion for soccer and national pride makes a full-blown repeat during the main event unlikely. But “Black Blocs” — shifting, leaderless groups of youths who march dressed in black, hooded and masked, and seek violent confrontation with the police — have no such qualms.

Esther Solano of the Federal University of São Paulo has interviewed self-identified Black Blocs. Without exception, she says, their aim is to disrupt the tournament. The police are seeking to avoid that by sharing intelligence and monitoring protest-related websites. But the blocs’ amorphous nature makes judging the success of the police almost impossible.

Another risk for Rousseff is that at least one World Cup venue may have to be scratched. That would be a big embarrassment, since tickets for games in all 12 stadiums already have been sold. Although all were supposed to be ready by now, six have been held up by cash-flow problems, strikes and accidents. The fatal collapse of a crane in November at São Paulo’s new stadium, which is to host the opening match, has left no room for further delays.

Despite these banana skins, Rousseff will be difficult to beat. Recipients of the Bolsa Família, a stipend that goes to 14 million poor families, are much more likely than other Brazilians to approve of her.

A false rumor in May that the handout was about to be axed caused near-riots in deprived northeastern towns, a reminder of this constituency’s size and power. Other policies identified with the president, such as importing Cuban doctors to work in poor areas, also are rated far more highly by the masses than the elite.

Despite Brazilians’ hunger for change, the challengers will have to persuade voters that much would stay the same if one of them is to win.

Copyright 2013 The Economist Newspaper Limited, London. All Rights Reserved. Reprinted with permission.