It is Sunday afternoon and the people of Tizimin, a modest market town barely 100 miles west of Cancun but far removed from the prosperity of the tourist beaches of the Caribbean, are spilling out of brightly coloured bars after seeing Mexico beat Iran 3-1 in the World Cup. But before going home, they have one more spectacle to enjoy.
By the hundreds - many of the women dressed in the white embroidered dresses of Yucatan's Mayan heritage - they stream on foot and by bicycle into the main square enclosed on two sides by an 18th-century Franciscan cathedral and ruined convent. Waiting for them in the blazing sun are row upon row of low wooden seats facing a make-shift stage festooned in yellow banners and plastic bunting.
If the hearts of most Mexicans are beating harder in these days of early summer, it is not just because of soccer. Less than three weeks from a presidential election, they are facing a stark and potentially portentous choice: to support the candidate of the ruling centre-right PAN party of outgoing president Vicente Fox, or tack abruptly to the left with the socialist PRD party, whose charismatic, populist candidate, Manuel Andres Lopez Obrador, 52, is bringing his raucous campaign caravan into Tizimin today.
With so much at stake in a country that only saw democracy take hold fully in 2000 when Fox ended more than seven decades of single party rule, it is a race that has inevitably turned vicious, with insults and dark allegations traded daily and even a botched shooting in Mexico City involving family members of a jailed businessman claiming to have a video showing aides of Lopez Obrador accepting bribes.
Mexicans are entirely unaccustomed to political suspense of this kind. For several months, polls have shown Lopez Obrador in a dead heat with his PAN rival, Felipe Calderon. Yesterday, a new survey published in La Reforma newspaper gave the leftist a tiny lead of three points. Not too far behind in third place is the other main candidate, Roberto Madrazo, of the old PRI.
Whatever happens on 2 July, it is not just Mexico that will feel the effects. Latin America has seen a dramatic shift to the political left in recent years, notably with the coming to power eight years ago of Hugo Chavez in Venezuela, followed by Nestor Kirchner in Argentina and, most recently, Evo Morales in Bolivia. Mexico, which is not only the immediate southern neighbour of the United States but also its largest trading partner, will emerge either as a bulkhead against the powerful populist tide or as the latest - and surely the most important - country in the region to embrace it.
If Calderon, 43, who has been distracted in recent days by allegations from the Lopez Obrador camp of unethical business dealings involving his brother-in-law, finally fends off the leftist challenge, it is the economy he will thank. After years of mediocre performance under Fox, the country achieved 5.5 per cent growth in the first quarter of this year with oil profits pouring into the national treasury. "It's the most important factor," says Cesar Castro of the Center for Economic Analysis in Mexico City. "The economy is doing well and Calderon is capitalising." The housing market is healthy, the peso is strong and inflation, for so long the plague of Latin America, is under control. More broadly, there is evidence that under President Fox, the middle class in Mexico has begun to expand.
It is precisely because of this progress that much of the business class and the educated lite view the possibility of a Lopez- Obrador victory with dread verging on panic. They worry that the model of open trading and fiscal conservatism followed by Fox will be abandoned and that, instead, Mexico, would fall back into old habits of out-of-control social spending and protectionism with rising debt, renewed inflation and perhaps a flight of …