If Mexico's elections, to be held this weekend, were decided solely on the size of campaign rally crowds, then Cuauhtemoc Cardenas, candidate for the centre-left Party of the Democratic Revolution (PRD), would sweep into office. Twenty thousand people turned out for his final hurrah on Sunday.
Mexico City's central square was transformed into an ocean of yellow flags, hats and banners, with not an inch of space to move in, where workers, intellectuals, students, environmentalists and families provided a deafening chorus of support for Cardenas, "the engineer", and his ally, Andres Manuel Lopez Obrador, candidate for mayor.
Mr Cardenas, trailing a distant third in opinion polls, has filled public squares and stadiums the length and breadth of the country, doggedly reiterating his vision of a more humane political system within the free-market economic model. Mr Lopez Obrador, a dynamic and charismatic politician, is leading his opponents two to one in the polls, certain to become mayor of the biggest city in the world.
"Duro! Duro!" roared the crowds when Cardenas took the stage, invoking the PRD's traditional war cry, "Let 'em have it", against the oldest one-party state in the world.
"We haven't abandoned our principles and we're not looking for jobs," said Mr Cardenas, rejecting a call from fellow opposition candidate Vicente Fox, who urged him to drop out of the race and give him his votes. Mr Cardenas is widely believed to have won the presidential elections in 1988, when initial results gave him a lead over ruling party candidate Carlos Salinas.
The computer system mysteriously crashed, only to recover several days later, ratifying Mr Salinas as president. Mr Cardenas lost support when he failed to contest the controversial result. The PRD has suffered brutal repression over the past 10 years, with 600 activists killed by state security forces, a decisive factor in deterring rural activism. Reports from Guerrero State this week indicate that Mexican army troops have set up camps outside villages sympathetic to the PRD, preventing activists from campaigning.
Mr Fox, a former Coca-Cola executive representing the centre-right National Action Party (PAN), addressed a huge crowd in Mexico's central square on Saturday at a spectacular final rally marked by rap music and fireworks. He offered to name a broad-based cabinet and called on Mr Cardenas to avoid "collective suicide" by dividing the opposition vote. Mr Fox also acknowledged that without the PRD votes, the ruling party was likely to win next Sunday's vote.
The PAN crowd was largely middle- and upper-class, as befits their conservative, pro-business profile, but the momentum of the campaign, growing in recent weeks, has attracted a working-class base, impatient to see the PRI out of office.
In addition, the PAN has drawn some of the PRD's intellectual support to its side, on the grounds of the so-called voto util, or tactical vote, which argues that a vote for the PAN is more likely to end PRI rule.
The Institutional Revolutionary Party (PRI), 71 years in power, enjoys a slim lead in the polls, yet attracted just half the PRD numbers to its final rally in Mexico City last week. The PRI event also offered a free concert by Juan Gabriel, one of Mexico's top crooners.
The PRI has focused its batteries against Mr Fox, highlighting his "foreignness" (his parents were immigrants to Mexico) and accusing him of "betraying the country" after the revelation that he received campaign funds from foreign companies, forbidden under Mexico's electoral code.