In 2007, Ada Colau put on a black leotard, a yellow cape, and a Zorro mask and gate-crashed a campaign rally in Barcelona.

For two and a half minutes, Colau commandeered cameras, holding up a cardboard sign—“Housing Out of the Market, Like Education and Health”—while she delivered a speech on irresponsible development. “We don’t want to hear that the solution is to build more,” Colau told the crowd gathered in the small city square. “We have devastated our territory more than enough. There are a lot of houses. What we need is that these houses fulfill their social role.” When she was done, she dashed between a pair of parked cars and sprinted down the street.

She didn’t know it then, but her appearance as a superhero was one of the first steps on a path to city hall. In June she was elected mayor of Barcelona, with the support of a coalition of leftist political parties. She campaigned on fighting inequality.

The Spanish economy in 2007 was afloat on an enormous housing bubble, and real estate was rapidly becoming unaffordable. She had launched a prescient protest. “The government was making a show of success: ‘The Spanish Miracle,’” says Colau, 41. She’s wearing a long, casual cardigan sweater and sitting at a small conference table in a corner of her office. “But the people were already suffering, because the prices of houses were very high.”

Donning the mask and cape—and videotaping the stunt—was a way to call attention to an issue she felt none of the candidates for mayor were appropriately addressing. “In a media culture like ours, you have to find ways to be seen and heard,” she says. “It worked well. The message was, ‘You have to be a superhero to survive in this city.’ ”

Colau rose to local and then national prominence as an activist in the wake of the 2008 global financial crisis, emerging as one of the most vocal critics of the government’s austerity policies. She led a movement that faced down banks over foreclosures and organized protests outside the homes of conservative lawmakers and was an active member of Spain’s Indignados, the protest movement that inspired Occupy Wall Street.

Her election—as the head of her party, Barcelona en Comú, a hastily formed leftist coalition—puts her at the forefront of a leftward swing in Spanish politics, along with the recently elected mayor of Madrid, Manuela Carmena, and the leaders of the insurgent Podemos party. Since taking office, Colau has shown no sign of blunting her approach. “Barcelona is a clear example of a global city,” she says. “Billions of euros circulate in this city every year. But they’re distributed badly. The inequality here is enormous. It’s out of control.”

Colau’s office is on the second floor of city hall, an art- packed 15th century Gothic palace with an 18th century neoclassical façade. She is the first woman to hold the city’s highest office, and she’s said she’d like to update the décor in the mayor’s receiving room with portraits of important women from Barcelona’s history. So far, however, the only change she’s made is to affix a piece of printer paper to the door to her office. It reads, “Let us never forget who we are and why we are here.”

Colau is at once businesslike and engaging, laying out her arguments as if they were cards on a table. When the subject is emotional—such as the photographs of a 3-year-old Syrian boy, Alan Kurdi, dead on a Turkish beach—you can hear it in her voice. When she wants to stress a point, she smiles or leans towards her interlocutor.

Colau sees parallels between housing and tourism; she worries the latter’s growth is hurting citizens and has declared a one-year ban on new hotel licenses. She has angered the Spanish government by removing a bust of former King Juan Carlos from city hall’s main chamber; announced her intention to rein in Airbnb; and taken aim at banks, threatening to fine those that keep their properties empty, rather than rent them out at subsidized rates.

“As mayor, I can talk to the banks on a more equal footing than I could when I was just a citizen,” she says. “There’s a wide consensus to say, ‘Guys, we need these houses, not to speculate but for the families that need them. First we will offer you the opportunity to collaborate and lend us these houses that you’re not using and that aren’t going onto the market. We’ll improve them and put them to use. And if you don’t want to collaborate, we’ll try other instruments to give you an incentive.’ ”

In early September, Colau held a victory party, for herself and seven other leftist Spanish mayors who had recently taken power, in a community center in a former train station. Colau was the last to take the podium, and she gave an impassioned speech on topics ranging from violence against women to the plight of refugees to subsidized meals for schoolchildren. The unifying theme once more was the fight against inequality. “The crisis we’re facing is not only economic or social,” Colau said. “It’s a primarily political and above all ethical crisis, one that has taken place under decades of governments that have been hostage to the 1 Percent.”

Two months earlier and 1,100 miles to the east, Greece had held a referendum on the terms of a bailout of its debt in which voters roundly rejected conditions imposed by creditors collectively known as the troika—the European Commission, the European Central Bank, and the International Monetary Fund. Shortly after, Athens was forced to accept even harsher terms to avoid being ejected from the euro zone. “We give our full support to Greece,” Colau told the applauding crowd at the community center. “It must not surrender. Let them know that in southern Europe, the democratic revolution is unstoppable, that they are not alone, that we are here to stand up to the troika and the criminal markets.”

Her election is part of a destabilization in European politics as traditional parties have wilted, providing opportunities for anti-establishment candidates. Colau also comes out of a long history of protest movements in Barcelona. It’s the capital of Catalonia, which is linguistically distinct from the Spanish-speaking regions of the country. As Spain’s second-largest city, Barcelona has always been a counterweight to the central government in Madrid. It was the epicenter of the country’s anarchist and labor movements in the early 20th century and a Republican stronghold during the Spanish Civil War.

The city has also been home to a growing Catalonian independence movement. The same discontent that opened city hall’s doors to Colau has brought hundreds of thousands of people into the street, demanding a chance to redefine their relationship with Spain. Madrid has consistently declared the independence movement in violation of the constitution. One of the campaign’s leaders, Artur Mas, who is president of Catalonia, has called regional elections for Sept. 27, pledging to start the secession process if parties in favor of independence get a majority of seats in the Catalan parliament.

Independence from Spain has never been an important issue for Colau; while she supports the right of Catalonians to decide, she hasn’t taken a strong stance on how they should vote. “Nationalism as a subject has never interested me,” she says. “But democracy, yes.”

Despite the city’s protest roots, its politics have been remarkably stable since democracy was reintroduced to Spain in 1978. Until the global economic crisis, the left-wing Partit deis Socialistes de Catalunya (Socialists’ Party of Catalonia) won every election. Then, in 2011, voters elected a center-right government, only to reject it four years later in favor of Colau even though the economy had started to grow again.

“When you start recovering, there are people who are going to be able to grab the hook and rise,” says Antoni Vives, a councilman who served as deputy mayor in the previous government. “And there are people who aren’t. Those are the people who voted for Ada Colau. We were not able to explain to them that we care for them, and that the prosperity will eventually reach them.”

In a country with a surprising number of politicians who are clumsy communicators, Colau stands out as a skilled and emotive speaker. In addition to traditional street rallies, her campaign organized its supporters to push hashtags into trending topics. Among its most successful social media efforts was an autotuned YouTube video of Colau singing a lively campaign song, her charisma shining through as she breaks composure between takes.

“It was a way of trying to connect with people who are difficult to connect with in the traditional way,” says Joan Subirats, a professor of political science at the Autonomous University of Barcelona who helped plan her campaign. It worked: Turnout in the 2015 elections was higher across the city than it had been four years earlier, and it rose much more in the poorer neighborhoods where support for Colau was strongest.

Colau came of age as an activist during the anti-globalization movement of the 2000s. Spain generally, and Barcelona in particular, has developed a tradition of theatrical activism, and Colau has spent most of her adult life in the thick of it. It was the housing battle, though, that made Colau a national figure. Under Spanish law, when a bank forecloses on a mortgage and seizes a house or apartment, only part of the debt is wiped out. The rest remains on the books, and the owner isn’t able to declare bankruptcy to escape the debt. The bank has claim to all assets, not just the house.

“The president of the government had explicitly told the population, ‘You have to buy a house because it’s the most secure investment, the best thing for your country,’ ” says Colau. “Millions of people who weren’t trying to speculate, or to be rich, but who thought they were doing the most responsible thing, the safest thing, discovered that they had done the worst thing in their lives, and that there was no way to escape.”

In 2009, Colau and a handful of other activists formed a grassroots organization called the Platform for People Affected by Mortgages—known by its Spanish acronym PAH. “She’s a natural leader,” says Lucía Martín, one of the group’s founders. “It’s not that she says, ‘OK, I’m going to be the leader.’ It’s that everybody looks around and says, ‘Yes. Her. She looks like she can do it.’ It became really obvious.”

One of the first people PAH assisted was Matías González Barquero, who had taken out a mortgage on his home to soundproof his bar at the request of the municipality. González was forced to close the bar in 2009 after a partner died and another fell sick. As a small-business owner, he was ineligible for unemployment, and soon he couldn’t pay his mortgage.

When he attended his first PAH meeting in 2010, his apartment had already been put up for auction, but it had failed to sell, and he hadn’t moved out. When González was scheduled to be evicted by police in March 2010, the group obtained a period of leniency from a judge. Over the next year and a half, PAH blocked two other eviction attempts, mobilizing some 300 people to block the entrance to his apartment. Colau was with González in his house, coordinating the protest from behind locked doors. “She said, ‘You keep calm, we’re going to make it,’ ” recalls González. “When she was facing the banks, she was very tough. But with me, she was a very close person.”

In September 2012 the bank tried to evict González again. This time, he and Colau took the case to the company’s Barcelona headquarters. Colau brought her newborn with her. González dressed for the occasion in prison stripes. As a result of the showdown, the bank agreed to forgive the outstanding debt, and even paid for a van to move his belongings into a public apartment provided by the city.

The PAH campaign changed the dynamic between banks and their debtors. The group had stratospheric public support. PAH now can often stop an eviction with a phone call or a handful of demonstrators. “It used to be the case that I would go trembling to the bank,” says González. “Now it’s the banks that are trembling when we go there.”

It would be a stretch to say that the banks are trembling at Colau’s election. But they’re paying attention. As mayor, she has met with the heads of many of the banks she once protested against, reiterating her intention to enlist their support in expanding the stock of public housing. The tactic of fining banks with empty homes on their books is vulnerable to legal challenges, but the town of Terrassa, about a 40-minute drive from Barcelona, has already tried it, handing out its first fines last year and fending off a lawsuit.

“The main objective of the banks is to sell as soon as possible those empty houses. Unfortunately they can do nothing, given the weak housing market situation,” Encarna Pérez, a spokesperson for the Spanish Banking Association, said in an e- mail. Penalizing banks for holding properties they’d rather be rid of is “incomprehensible,” she added.

Tourism Industry Waits

Much of the business community has adopted a wait-and-see stance, especially regarding Colau’s views on tourism. “We have to be less dogmatic and more open to reality,” says Jordi William Carnes, director of the tourism board. “It’s not a question only of big business owners. The taxi driver, the hairdresser, the storekeeper, all these are getting advantages from tourism.”

Colau’s concern about tourism is, unsurprisingly, informed by her experience with housing. A tourism boom has transformed large parts of the city, especially the rambling medieval streets of the historic center, the neighborhood around the fairy-tale spires of Catalan architect Antoni Gaudí’s Sagrada Família Basilica, and some of the areas around the waterfront. La Boqueria market in the city center, for instance, where locals once did their shopping, has become a giant food court, with tour groups crowding around stands that previously sold fresh fish but now serve meals.

The overall effect—familiar to residents of such cities as Venice, New Orleans, or Rome—is similar to gentrification, as the influx of money and soaring property values drives out local residents. Barcelona has some 10,000 registered tourist apartments and perhaps as many as 20,000 unauthorized rentals—most of them marketed through sites such as Airbnb—and as property owners have found it more profitable to serve the tourist market, rents have risen.

Colau has wasted no time signaling a change in the way the city approaches tourism. In addition to putting new hotel licenses on hold, she has questioned the appropriateness of using city money to subsidize Formula One racing and declared that the city wouldn’t bid for the 2026 Winter Olympics.

When Barcelona hosted the Olympics in 1992, it had so few hotels that organizers chartered 11 cruise ships to accommodate visitors. In 2013, Barcelona was the fourth-most-visited city in Europe, according to PwC, with hotel room demand outpacing supply despite hotels opening at an average rate of about 10 per year. That’s made the city’s hotels among the most expensive on the Continent. In the past four years, tourism has grown by 18 percent; the industry accounts for 12 percent of the city’s gross domestic product. For Colau, the effect is worryingly reminiscent of the housing bubble—a socially disruptive surge in investment that enriches a few at the expense of many. “There’s strong growth, and this should serve as a warning, because it can generate imbalances,” she says. “We don’t want to repeat the errors of the real estate boom.”

The general consensus in Barcelona is that Colau, like insurgent politicians across Europe, has entered unfamiliar territory. Her ability to make sure she is seen and heard is unquestioned, but her success will depend on her skills as a manager and her ability to turn her proposals into policies. “Many cities would like to have the problems that Barcelona has,” says Mateu Hernández Maluquer, chief executive of Barcelona Global, a business lobby. “Her diagnosis is OK. There’s a need to better manage tourism. It’s the prescription we’re still waiting for.”

This article was written by Stephan Faris from Bloomberg and was legally licensed through the NewsCred publisher network.