Leftist Andres Manuel Lopez Obrador has raised the stakes in his bid for the disputed Mexican presidency, from leading mass marches to heading blockades that have paralyzed parts of the capital.
Ramshackle protest camps reduced Mexico's financial center to a shadow of itself, and the silver-haired presidential candidate says it is just the start of a campaign of sustained "civil resistance" against alleged electoral fraud.
Lopez Obrador, who stepped down as Mexico City's mayor to run for president, narrowly lost the July 2 vote to conservative Felipe Calderon, according to the official count. He is demanding a vote-by-vote recount and challenging the results in court.
The protests have not been violent, but tension is rising.
On Monday night, thousands of Lopez Obrador supporters at the main protest camp in the capital's central plaza shouted curses and threats at Mexican and foreign reporters, who they claim have been biased against their candidate.
Lopez Obrador promised the crowd that the protests will intensify and the streets will remain under siege until Mexico's highest electoral court, the Federal Electoral Tribunal, rules on his request for a recount.
The court must declare a president-elect by Sept. 6. President Vicente Fox, of Calderon's conservative National Action Party, leaves office on Dec. 1.
"For some people, our protests are an annoyance, but without sacrifice there is no justice or liberty," said Lopez Obrador, who was sleeping in a tent for the second straight night Monday. "We live in crucial moments in Mexico. They are trying to stop democracy for millions."
Marches and protest camps are common in this megalopolis of 20 million, but the encampments were on a scale that hasn't been seen in recent Mexican history.
The blockades demonstrated that the charismatic former mayor can mobilize thousands of supporters to disruptive protests and that authorities are hesitant to take action against them. Mexico City's government is controlled by Lopez Obrador's Democratic Revolution Party and federal authorities have promised not to intervene unless their local counterparts ask for help.
The camps, set up between gleaming office buildings in the heart of the capital, forced many businessmen in suits to hike kilometers to their offices on Monday, caused the stock market to dip and hurt downtown businesses and tourist attractions.
Salesman Alejandro Lara, 33, walked 3km up Mexico City's fashionable Reforma Avenue, normally teeming with cars, before he began yelling at protesters.
"I'm either going to have to get up at 5am every day, or ask for a vacation," Lara said angrily. "It's too bad, because I supported Lopez Obrador. But now, after this, I wouldn't want to have him governing us. He scares me."
Calderon's aides and top business leaders have demanded that Mexico City authorities move in and do away with the camps.
"What they're doing is kidnapping Mexico City," said Cesar Nava, a National Action spokesman. "We see that as an unacceptable, partisan act that is absolutely contemptuous of democracy."
But Mexico City Mayor Alejandro Encinas said his government will not send police against the protesters.
The protesters include grand-fathers, single mothers and families camping out together.
"We're blocking the road, but it is better than blocking the path to democracy," said Adrian Bejerano, a 42-year old psychologist.