MEXICO CITY — Mexico's presidential vote was thrown into turmoil late Sunday, with both leftist Andres Manuel Lopez Obrador and conservative Felipe Calderon claiming victory as election officials announced that the two men were separated by a razor-thin margin.
The Federal Election Institute said the result would not be known until Wednesday and that the margin between the two leading candidates would probably be less than a percentage point.
Electoral institute President Luis Carlos Ugalde announced that a "quick count" based on a sample of the votes from about 7% of the precincts had produced a result within the margin of error. Only a full count of the more than 40 million estimated votes could determine the winner, he said.
Lopez Obrador nonetheless announced victory, soon followed by Calderon. Both said late Sunday that their own data showed them winning.
The leftist candidate told supporters late Sunday that the government wanted to cheat him out of a larger victory. "I want to inform the people of Mexico that according to our calculations we have won the presidency," Lopez Obrador said. The final difference, he said, would be 500,000 votes.
Calderon appeared moments later, to say that numerous private exit polls showed he would win. "Today the trends announced by several firms ... show that we have won the presidential elections," he said.
Lopez Obrador supporters gathered in the Zocalo, this city's central square, and shouted, "Fraud! Fraud!" Calderon backers at his National Action Party headquarters chanted, "We did it! We did it."
President Vicente Fox called for calm.
"The citizens can have the full certainty, the confidence, that all the votes will be counted and respected," Fox said in a nationally televised address moments after election officials announced their finding.
Early this morning, with 66% of polling stations counted, Calderon's ever-narrowing margin over Lopez Obrador had fallen to 1.2 percentage points.
In the coming days, the muddied result is sure to provide a stern test for Mexico's democratic institutions, which are still struggling to emerge from a long history of corruption and authoritarianism.
Lopez Obrador's statements seemed to play to the worst fears of his supporters, who have long seen themselves as victims of political shenanigans.
