MEXICO CITY _ It was 4:15 a.m. on Monday, July 3, when I ran into Andres Manuel Lopez Obrador, the presidential candidate from the Democratic Revolution Party, as he was coming out of a hotel on Mexico City's verdant Paseo de la Reforma avenue. He seemed full of energy. He walked briskly among a score of collaborators, waved, smiled and quickly slid into his old car.

He showed no signs of fatigue in spite of his being one of the principal protagonists in the longest night of recent Mexican history. The other contender in this epic event was Felipe Calderon, the candidate from the (ruling) National Action Party. Just a few hours later, each was already talking to the press.

The two candidates have thus created a "train crash" situation, so feared by analysts. Though the president of the Federal Electoral Institute (IFE), Luis Carlos Ugalde, asked them on Sunday night to be restrained, responsible and to wait for the official results, both declared themselves winners of the presidential election, paying little heed to the appeal of the top electoral official.

This clearly eroded the strength and credibility that the IFE and Ugalde are dependent on. If one of the two candidates disputes the official results and refuses to acknowledge defeat, Mexico could spiral out of control into chaos and uncertainty. With thousands of supporters of Lopez Obrador and Calderon having taken to the streets to celebrate their respective candidate's announcement, it is now going to be hard to appease them and say: "I made a mistake; I am not the winner; go back home."

At the end of the day, whichever candidate wins is going to preside over a divided Mexico. Only one in eight Mexicans voted for this next Mexican president. And what's at stake are the very different courses that Mexico will take, depending on who wins. It is not merely about leaning right or left. It is also about verticality. One of the candidates represents the people at the top, while the other represents the folks at the bottom. And it may be only a few votes that will determine the difference.

Whether it is Lopez Obrador or Calderon who takes office, either one will have to do so with a huge burden. The new Mexican leader will literally have to drag the country forward. And therefore Mexico will have a hard time competing on an equal footing with countries like China and India. To create a million new jobs a year _ so that Mexicans won't have to migrate to the United States for work _ will be a titanic task. Will Mexico be able to look to the future or will it remain stuck in the past?

The situation becomes even more contentious because the Chamber of Deputies and the Senate are almost equally divided in three. The new occupant of the Los Pinos presidential residence will be forced to negotiate with the two main opposition parties to gain approval for any significant reform to Mexican laws. The incumbent, President Vicente Fox, was frustrated in that attempt, and there's nothing to indicate that whoever replaces him will be any more successful.

In Mexico, there's no blueprint for the country that has the support of every political party and social sector. There's no national consensus that would allow progress in education, health and the economy, independent of the chief executive. So every six years, Mexico experiences an earthquake.

Mexicans have done their part by voting. Some 44 million went to the polls (60 percent), a percentage superior even to those in the United States and several European countries. Now, the responsibility lies with the leaders.

If the candidates behave with discretion and prudence, the IFE with efficiency and Fox with neutrality, Mexico may have the chance to consolidate its young democracy, which is just six years old. But, if personal interests, ambition and provocation predominate, then conflict, violence and suspicion lie ahead.

Mexico has a sad history of resolving its conflicts with violence. The 2006 presidential election should not become another page in that history.