NEWS ANALYSIS : Messy Electoral Standoffs Pose Dilemma for Mexico : Politics: With U.S. trade pact at stake, leaders are eager to show commitment to multi-party democracy.

More than three months after elections in the western state of Nayarit, thousands of opposition supporters marched through its capital last week, protesting the overwhelming victory of the ruling-party gubernatorial candidate.

It is a recurrent scenario in Mexico, where charges of fraud seem to mar every election, from small-town mayoral contests to presidential races. The opposition also challenged recent results in the states of Guerrero, Coahuila and Mexico.

In Nayarit, where violent police repression of demonstrators and Roman Catholic Church protests added to the controversy, there is already speculation about an interim government, similar to those installed in four other states where angry citizens rejected official victories in recent years.

For the Mexican government and the long-dominant ruling party, its credibility badly shaken after decades of electoral manipulation, the persistent challenges are part of an increasingly thorny dilemma: how to persuade skeptics that its nominees can win elections honestly.

Even when its candidates win big--as happened in the governor contests in Nayarit and Coahuila--allegations of electoral wrongdoing tend to dilute the triumphs, battering party prestige anew. And the timing of the current round of disputes is troublesome.

With the North American Free Trade Agreement before the U.S. Congress, party leaders are eager to avert messy electoral standoffs that tend to undermine Mexico City’s proclaimed commitment to multi-party democracy.

Meantime, next year’s presidential elections are approaching. Authorities want to avoid a repeat of the tarnished victory of President Carlos Salinas de Gortari, whose razor-thin majority in the 1988 elections prompted widespread charges of cheating.

Last week, Amador Rodriguez Lozano of the ruling Institutional Revolutionary Party--known by its Spanish acronym as PRI--called on the opposition to exercise “dignity in defeat” and not resort to what he characterized as knee-jerk, post-election cries of fraud.

But opposition leaders were unfazed, insisting that institutional fraud in Nayarit and elsewhere belies Salinas’ much-discussed electoral reform efforts.

“Election results here are completely lacking in credibility,” said Ricardo Pascoe Pierce, international coordinator for Cuauhtemoc Cardenas, presidential hopeful of the leftist Party of the Democratic Revolution. “The PRI is clinging to power desperately.”

Recent electoral revisions have made it more difficult for coalition candidates, probably harming Cardenas’ presidential prospects.

In Nayarit, an agricultural state of about 1 million, Cardenas’ party mounted a spirited gubernatorial challenge in a contest tainted by mudslinging.

A victory would have represented a major boost for Cardenas’ 4-year-old party, which controls no statehouses. (The nation’s three opposition governors are all members of the right-wing National Action Party, which has long served as a kind of loyal opposition to the PRI.)

According to official results, Rigoberto Ochoa Zaragoza, the PRI candidate in Nayarit, won almost 60% of the July vote.

The opposition promptly took to the streets, alleging that ballots were stuffed, individuals were allowed to vote more than once and the ineligible had been allowed to vote--all maneuvers that PRI has been accused of before.

With the electoral fraud still under investigation, Ochoa took his post in the state capital of Tepic two weeks ago, triggering protests.

The new government reacted in force. Police reportedly beat dozens of demonstrators and detained scores, including a priest whose church--a sanctuary for protesters--was tear-gassed.

Among the many denouncing the response was the Catholic diocese, which, in a statement sent to Salinas, condemned “the violent repression against protesters who seek to defend their rights through constitutional means.”

The denunciation was noteworthy in a nation where the church hierarchy is seldom identified with the left.