It may be that the candidates of Mexico's governing party, the PRI, actually got the most votes in last week's elections in the states of Nuevo Leon and Sonora. But no one may ever know for sure. Ballot fraud was pervasive. Poll watchers of the main opposition party, the PAN, were disqualified before the election or physically ejected from polling places. Voting lists were inflated with duplicate and false names. Some ballot boxes were stuffed. Others were simply snatched away and driven off in speeding cars. These were not isolated practices.

It's dismaying to observe this tawdry performance in a nation that is capable of doing better and at a time when Latin nations with democratic traditions far less robust than Mexico's -- the latest example is hapless Bolivia -- have conducted fair elections. We say this, we trust, in due and humble awareness of past vote fraud in the United States.

In Mexico, vote fraud has been a widely conceded feature of a political system that has, over a run of more than 50 years, brought the country economic growth, political stability and a record of considerable respect for civil liberties. The PRI has won all presidential and nearly all congressional and gubernatorial elections in Mexico since it was formed. Many of its operatives and supporters believe it would be against the national interest for it to lose any major contest.

But Mexico's president, Miguel de la Madrid, made a point of promising beforehand that elections would be fairly conducted. One of the dismaying things about the Nuevo Leon and Sonora elections is that they suggest there are limits to the control the president -- a technocrat who has made his career in Mexico City and not in electoral politics -- maintains over the local PRI organizations.

Mexico may be at a critical point and is certainly at an uncomfortable point in its gallant effort to whittle down its huge foreign debt and to get its economy in shape for sustained growth. Polls taken before the Nuevo Leon and Sonora contests suggest that the PRI was holding onto a lead in areas where the PAN seemed to have great potential. The massive electoral fraud, by casting doubt on the reported outcome, also casts a shadow over the legitimacy of the ruling party's majorities. That's not helpful for a country that has been working hard at home and abroad to build confidence in itself as a major economic and political power.