By Franc Contreras
BBC News, Mexico City
Politics has often been a violent affair in Mexico. And after decades of virtual one-party rule, July's parliamentary election has caused bitter recrimination.
Mexicans have a lack of trust in their political institutions
Some have called outgoing president Vicente Fox a "traitor to democracy", allowing his party's candidate, Felipe Calderon, to win. The row highlights the cynicism most Mexicans feel towards their politicians and institutions.
I got word last week that there would be yet another massive demonstration in the capitol's main square, the Zocalo.
Out in the street I realised that I had put on a white shirt and blue jeans. Blue and white are the colours of the conservative right candidate, Felipe Calderon. The rally I'd be attending would be filled with people who disdain him.
They are die-hard supporters of the centre-left candidate, Andres Manuel Lopez Obrador, whose colours are yellow and black. I quickly changed my shirt and went downtown.
By the time I got to the Zocalo, the side streets leading up to it were jammed, once again, with angry people demanding a full recount of all the ballots in the July presidential election.
Since 2000 Mexico has been changing dramatically
Many carried signs declaring President Vicente Fox "a traitor to democracy". They believe he orchestrated the election to favour his party's conservative candidate, Felipe Calderon.
People in the crowd held up posters, declaring the top election official "a wanted criminal".
Most of Mr Lopez Obrador's supporters are poor Mexicans who truly believe that election fraud took place here, and this, for them, is nothing less than a battle for Mexico's democratic soul.
Supporters of Lopez Obrador's (pictured) have cried foul
One woman in the crowd told me, "What do we have to lose by being here? Our pay checks barely allow us to pay the rent and keep our children fed and clothed."
She reminded me that Mr Lopez Obrador has promised to make the poor his top priority. But that pledge won't matter much, unless he becomes the president.
It has been a difficult prospect all along. Last year, government officials from Mr Fox's administration tried to charge the leftist candidate with a minor crime.
By attempting to convict him, they would have stripped him of his right to run for public office. But international pressure came down on the Fox administration and the case was thrown out.
During the presidential campaign, Mr Lopez Obrador's rivals compared him to Venezuela's firebrand leftist president, Hugo Chavez. Mr Calderon's television ads regularly labelled the leftist politician as "a danger to Mexico".
That struck me as deeply exaggerated and clearly designed to manipulate public opinion. The Federal Electoral Tribunal agreed, and forced Mr Calderon to remove the ads from TV.
I've been living in Mexico City for 10 years. During the last four, Mr Lopez Obrador was mayor here. He showed himself to be at least as pragmatic as his conservative rival.
Both men know that they cannot ignore business interests or the growing throngs of poverty-stricken Mexicans.
Protests have paralysed Mexico's capital in recent weeks
As I waded deeper into the crowd, I felt very claustrophobic - pressed up against a stone wall. The crowd kept coming. I called out, "keep calm, keep calm, don't push." It was more a message to myself as my anxiety grew.
Mr Lopez Obrador began his speech with charismatic words, reminding his faithful followers of the historic inequalities they have suffered over generations.
He called for a full recount. Only then, he said could fellow Mexicans rest assured that the election was fair.
Mr Lopez Obrador has shown the world that he can call his supporters out in huge numbers when he wants to. And that they can paralyse key parts of the city's financial district.
Lack of faith
But his talent for organising explains only part of the reason why his followers take to the streets this way.
The unspoken factor in all this is the deeply-rooted lack of trust that Mexicans have in their government, officials and institutions. Sure, this is common feeling around the world. But Mexicans' lack of faith seems especially acute.
Lopez Obrador supporters have rallied round their candidate
It can be found from the northern deserts on the US border to the country's tropical regions and in the deep, indigenous south near the border with Guatemala.
This is part of the legacy of more than 70 years of single-party rule. Citizens would know a year before each election who their next president would be.
Invariably, he would belong to the Institutional Revolutionary Party, or PRI. The party used all manner of fraudulent techniques to win 16 consecutive presidential elections.
The regime got so good at it, that Mexicans created a special vocabulary for vote fraud. Ballot boxes stuffed with PRI votes were called pregnant urns. A folder containing ballots for the ruling party's candidate was called a "taco".
Moment of truth
After the historic presidential election in 2000, voters peacefully brought an end to that regime. That was unprecedented. Since the Spanish Conquest, regime change in Mexico had always been a violent business.
Since 2000 the country has been changing dramatically. It is still in a process of maturing and desperately trying to consolidate its democracy.
In a way the current stalemate is a test for the Mexican people themselves. This is their moment of truth.
If the judges rule that Mr Calderon is the winner, will large sections of Mexican society believe them? Or will they take to the streets and make it impossible for him to govern?
Everyone is talking about what happens next. But right now, what matters most is whether Mexicans have faith in the judicial process and whether they will have to think twice about what colours to wear on their next trip downtown.