For centuries the Zócalo has been the centre of national life in Mexico, from the brutality of the Conquistadores to Independence in 1810, and from the revolution a hundred years later to the national protests of today.
The Zócalo is a magnificent space, at least four times the size of Trafalagar Square, with the National Palace on one side, the huge cathedral on the other, and in one corner part of the old Aztec City so brutally destroyed by Hernan Cortez and the Conquistadores. It is routinely the site of camps and protests by workers and the landless victims of Mexico's neoliberal growth policies; but last Saturday, this national centre saw something very different.
For the fifth time since the hotly disputed election of July 2nd, the supporters of Lopez Obrador came to the square, this time for a national convention. For the uninitiated, the title CND (Convencion Nacional Democratica) was confusing - but the purpose was clear. After the refusal of the electoral commission and the courts to order a full recount of the votes from July when Lopez Obrador "lost" by a handful of votes, the parties of the coalition called for a national convention to decide the next step in this peaceful protest.
Essentially, there were two issues at stake: whether to recognise the election of Felipe Calderon, and if not, whether to issue a rival declaration of president, essentially setting up a parallel government.
The Zócalo was filled to overflowing, with more than a million protesters milling in the streets and listening to proceedings on loudspeakers. The vote not to recognise Calderon was overwhelming, and only slightly less overwhelming was the vote to name Andres Manuel Lopez Obrador as president.
I observed the proceeding from intersection of Calle Bolivar and Calle do Motolina, and later from the square itself. Diversions like football on TV and endless vendors of maize cobs and tacos, as well as yellow hats and appropriate rain covers in the thunderstorm, did not distract from the sense of historic occasion. I cannot think of any European equivalent to the sheer scale and organisation of the protest.
This process is the culmination of months of protest and camps in the city that has had scant international recognition compared, for example, to the Orange Revolution in the Ukraine. One can only conclude that the principle demands of the people - an end to neoliberal economics and opposition to privatisation - did not fit into the pattern that Washington wants.
Whilst the supporters of the convention came from a diverse range of groups there was no denying the determination of poor and dispossessed people making a huge journey to the capital to have their voice heard.
Despite the media's claims of the convention's violent intent, there was none; in his address, Lopez Obrador made very clear the peaceful road he sees for protest, disruption and change.
His appeal is essentially a national one rooted in the history of Mexico.
Benito Juarez was the leader during the European intervention when French forces installed Emperor Maximillian on a non-existent throne. Juarez decamped from the City and led the fight back from Vera Cruz; eventually the invaders were put to flight, the hapless Maximillian executed, and the deeply unpopular Queen Carlota left to live out her life in exile.
Lopez Obrador invokes the appeal of national unity, the revolution of 1910 and the progressive constitution of 1917. More recent causes for protest are the elections of 1988 when the PRD candidate, Cardenas, was robbed of victory over the PRI (Party of the Institutional Revolution) through fraud and corruption. It turned out to be a pyrrhic victory; Cardenas then helped form the PRD, which many left the PRI to support.
The Mexican Sunday papers were confused as to how to report Saturday's events. It was supposed to be the national celebration of independence on 15th when the traditional cry "Viva Mexico" heralds independence. Afraid of protests President Fox made the traditional cry in a small town well away from his capital; the morning's military parade was watched by smaller crowds, some carrying posters denouncing him as a traitor, and then the capital was given over to the National Convention.
The mayor of Mexico City, from the PRD, supports Obrador and his Sunday speech outlining his plans for the City was supported by an overflow crowd who applauded throughout, particularly his pledges of school books, new schools and health; also his pledge to give this most polluted of cities clean air. The biggest cheer, however, was for his support for the alternate government.
Already the international ramifications are developing. At the Non Aligned summit in Havana, presidents Chavez and Moralles have made clear their preparedness to deal with Lopez Obrador; others will follow.
The media who welcomed Calderon's so-called election in July as the halting of the radical bandwagon of Latin America were premature. The huge disparities of wealth and power in the region have only intensified since the Nafta agreement. Crime in border cities like Cuidad Juarez is appalling, as is the degree of discrimination against non-Spanish speaking people; there are land disputes as traditional campesinos are forced off their land to make way for agri-business; the mining industry is in the midst of a huge industrial dispute over safety and conditions.
The USA, which has treated Mexico as its own back yard for decades, is in a quandary. The protests by the convention supporters have a popular resonance. Mexico is becoming the northern part of Latin America, not the USA's southern outpost.