Brazil's reluctant revolutionaries are struggling with success.

The Free Fare Movement, which advocates for the elimination of all transit fees, didn't expect to become the focal point of what some Brazilian media are calling the most important mass demonstrations in the nation's history. Nor did they imagine they'd be tapped as one of the few groups, if not the only one, to decide whether the protests grow or fade away in the coming days and weeks.

But that's the rapid evolution facing this "horizontally" organized wing of mostly young university students, who have been calling for the elimination of bus and subway fares since 2003. They've already won the cancellation of fare hikes that triggered the explosion of mass protests more than a week ago. Now, even after meeting with President Dilma Rousseff on Monday, the movement is sticking to its original platform: the complete zeroing out of transit fares.

More than anyone in this formless protest movement, the group has the power to extend the unrest that has shaken Latin America's biggest country and since wrapped in a litany of grievances, from woeful health services to the sky-high cost of hosting next year's World Cup and the 2016 Olympics.

"Look, we're not the owners of these protests across Brazil nor are we the only group behind them," said Caio Martins, a rail-thin 19-year-old university student helping orchestrate a Tuesday protest supported by the Free Fare Movement. "That said, we are one of the most organized groups involved in what's going on. I think that's why people have looked to us."

Outside watchers said now is the time for the group to press its demands, while it has the Brazilian government back on its heels. Doing that, however, will mean becoming an actual movement capable of expanding beyond its single-issue base, said Guillermo Trejo, a professor at the University of Notre Dame in the U.S. whose research focuses on social protests in Latin America.

"This is a crucial week for the movement because they're so strong right now," Trejo said. "The height of the power of the movement is this week. Whereas the leaders of the movement initially represented the transportation issue, they're now in a position to represent a much larger constituency."

Before police cracked down on a June 13 rally, the Free Fare Movement was a relatively obscure group — carrying out protests but not gaining much national traction. Its first transport protests did manage to briefly paralyze the northeastern Brazilian city of Salvador a decade ago, and its cause spread to the city of Florianopolis in the south the following year. In 2005, a national movement was born at the anti-capitalist World Social Forum held in Porto Alegre.

That low profile officially ended when Sao Paulo police fired rubber bullets, canisters of tear gas and stun grenades at the group's protest last week in a congested central area of the country's biggest city. One of Brazil's top newspapers had suggested the police crack down after an earlier Free Fare action destroyed buses, shattered storefront windows and blocked traffic.

More than 100 group members ended up injured in the police sweep, along with several newspaper reporters, two of whom were shot in the face at close range with rubber bullets. National outrage over the violence, fanned by social media, opened a Pandora's box of Brazilian discontent.

With the whole country now up in arms, some question the group's ability to continue winning concessions, like it did this week from several city and state governments that reversed public transport fare hikes.

For one thing, Free Fare's insistence on eschewing any leadership structure while encouraging the direct participation of all members has made it more difficult to put out a unified message. As a result, on Friday, one member had said the group was calling off all future protests, only to be contradicted two days later by another in the group, who insisted the demonstrations would continue.

When asked whether the organization's unconventional structure works, Martins stifled a laugh as he stood at the side of the small march in Sao Paulo.

"We reversed the fare hike! It works, it works," he said. "Well, at times some members have presented themselves to the media as if they were leaders of the movement when they're not. We don't have leaders. That aside, we have few problems."

Mayara Vivian, a member who met with Rousseff, showed no signs of backing down on pressuring the government despite Free Fare's structural challenges.

"It's one thing to talk, but we've got to see concrete action," she said. "Dialogue is an important step, but without action that guarantees improvements for the population, there will be no advances."

Street vendor Edmundo Pereira da Silva watched Tuesday's protest crawl down a main Sao Paulo road while peering from a hole in the wooden door of his tiny, disheveled concrete shack.

Like most people in the metropolitan area of 20 million people, he spends several hours and a large chunk of his disposable income on bus and subway fares. For that reason, he said he backed Free Fare's campaign.

"I hope for a better Brazil, of course. I want a different Brazil, with more quality, more confidence, with honest politicians and people who cast conscientious votes," he said, the stench of sewage strong at his door. "That's their fight — and we've got to at least try."

As a cold rain drenched the few hundred marchers, Martins skirted in and out of the crowd, quietly conferring with other group members at the front of the march before moving back into the mass.

"We've always maintained that we are solely focused on the issue of free transport," he said.

But now, after the mind-blowing protests of the past week, that is already changing, he said.

"Our fight is for the transformation of society."


Associated Press writer Marco Sibaja in Brasilia contributed to this report.