In April a sit-in among steelworkers in the west turned deadly. The next month came violent demonstrations outside Mexico City.
Now, thousands of dissidents in the southern state of Oaxaca have taken over this pretty colonial capital, shattering windows of hotels, spraying buildings with revolutionary graffiti, and causing the city to cancel its most famed festival of the year.
Over the weekend, gunmen attacked a radio station in Oaxaca that had supported a mass movement calling for the resignation of the governor.
While these flare-ups are driven by local circumstance, they share their origins in class friction and distrust of authority. These issues have long been part of Mexican society, but have now become overriding themes in the still-disputed July 2 presidential election.
"We are seeing a big awakening," says Wilfrido Mayren Pelaez, a Catholic priest in Oaxaca City who has been mediating between the strikers and the state government.
"People have changed.... Across the country, we are seeing that in different ways and with different expressions."
Protests over disparities are not new to Mexico's political landscape. Its 1910 revolution was sparked in part by peasants and the working classes seeking to overhaul the inequities exacerbated by the Porfirio Díaz dictatorship.
But many say that social tensions have reached a fever pitch, in part because of expectations and realities formed by the unraveling of 71 years of authoritarian rule by the Institutional Revolutionary Party (PRI), whose reign ended with President Vicente Fox's victory in 2000.
"In the case of Oaxaca, what we are seeing now is something that has been boiling for decades," says Rossana Fuentes-Berain, a political analyst at the Autonomous Technological Institute of Mexico. "It is emblematic of frustrations people feel in parts of the country."
The clashes in Oaxaca, which is closed off by metal barricades that are spray-painted with threats aimed at Gov. Ulises Ruiz, are taking place against the backdrop of the disputed presidential election.
The 2006 race, the closest in history, has the free-trade advocate Felipe Calderón winning with a little more than half a percentage point over Andrés Manuel López Obrador, an outspoken advocate of the poor – and has split the country along geographic and class lines.
In Oaxaca, an annual protest by the teachers' union morphed last month into a mass movement calling for Governor Ruiz's resignation when he ordered state police to clear out strikers from the teacher's union, who have been leading an annual protest for higher wages for 26 years.
The government response represents a heavy-handedness that observers say the people of Mexico will no longer accept. The repression, which included tear gas, angered union groups, farmers, and radical political organizations alike. They have banded together to demand his resignation, sleeping in shifts in the central plaza, or zocalo.
"The PRI bet that the traditional way of doing things would work," says Gloria Zafra, a sociologist at the Benito Juarez Autonomous University of Oaxaca. "But the people changed."
The power struggle in Oaxaca has drawn other embittered residents, protesters say, including activists from San Salvador Atenco, where the May demonstrations took place. One banner for "Radio Kapucha," a radio station formed by activists from Chiapas, makes reference to a crusade launched by Zapatista rebel leader "Subcomandante Marcos" this winter to expose what he called the inadequacy of all three main presidential candidates.
"It is time that we all come together and participate," says Mari Gutierrez, who teaches religion classes outside Oaxaca City and has joined a group of Catholic organizations camping out in the zocalo. "A lot of us are becoming conscious that the government [officials] are liars, and we need to join the people's fight against inequality and injustice."
Runner-up López Obrador, who lost by 244,000 votes, has submitted claims of voter fraud and requests for a full recount to the nation's top electoral court, which has until Sept. 6 to certify a winner. He announced at a rally last Sunday that he would launch a campaign of civil disobedience if his request for a recount were not granted.
No matter who wins, experts say, Mexico's next president will struggle gaining legitimacy in the eyes of a significant part of the population.
"This is a very contested election," says Ms. Fuentes-Berain. She says she does not expect unrest to replicate itself across the country, because Oaxaca and San Salvador Atenco are examples of movements that have been taken over by radical factions.
"But what we are seeing now is worrisome proof of how ungovernable a state can turn when there is no real good faith [effort] at negotiation ... on both sides," she says, referring to talks between the striking teachers and the government.
Protestors in Oaxaca are scheduled to meet Tuesday to discuss their next steps, says Father Mayren Pelaez. They had refused to negotiate any terms until Ruiz steps down, but they could reconsider that stance, he says. "If that happens, we have hope of beginning to talk again," he says.
But many protestors say that their goals stretch beyond the political future of Ruiz. Florentino López Martinez, a member of the Popular Assembly of the People of Oaxaca (APPO), the umbrella organization for the protest in Oaxaca City, says their struggle could become a national cause against the "neoliberal politics" that have defined Mexico as it has opened its markets to global competition.
"We are against repression, and we could provide unity for all the country," he says, "where the pueblo is fighting against the rich."
In voicing such rhetoric, the group has raised the stakes of the protest, with no clear end in sight. "[A solution] might take a long time, and a dramatic response," says Francisco Toledo, a famous Mexican artist in Oaxaca who has joined Father Mayren Pelaez as a mediator.