THE assassination Wednesday of Mexico's front-runner presidential candidate, Luis Donaldo Colosio, throws the country into a state of profound political uncertainty.
Colosio had just begun a campaign swing through a poor neighborhood in Tijuana, Baja California, when he was shot twice. The suspect in police custody is a 23-year-old self-proclaimed pacifist and trained industrial mechanic, according to Mexican authorities. Another man, reportedly an ex-federal policeman, is also in custody.
This is a ``brutal attack'' on democracy by ``those who seek to destabilize the country,'' said members of the Mexican Congress in a joint statement. Conspiracy theories are emerging, but no official explanation had been released at press time.
With less than five months before the elections, Colosio's death comes as a sharp blow to the ruling Institutional Revolutionary Party (PRI), for which he was the candidate. The party, which has not lost a presidential election since its founding in 1929, was already divided and weakened by a popular Indian uprising in the south and stiff opposition demands for electoral reforms.
The assassination comes on the heels of a series of disturbing events that have shattered Mexicans' confidence in their government and national security, and has given investors cause to question the political stability of the Mexican economic ``miracle'' so carefully crafted by President Carlos Salinas de Gortari.
In the past year, Mexico has suffered:
* The kidnapping last week of the president of the country's largest bank. A ransom between $50 million and $100 million has been demanded. The family, lacking confidence in the police, has asked them not to interfere.
* The siege of five towns in southern Mexico by about 2,000 Mayan Indians on New Year's Day. A 10-day battle with the Mexican Army ensued. A cease-fire and preliminary peace accord has been negotiated, but the rebels have not approved the accord and are still armed.
* The killing of Roman Catholic Cardinal Juan Jose Posadas Ocampo last May in what was officially described as a shootout between rival narcotics gangs at the Guadalajara airport. Mexican police were implicated in the shooting. Many Mexicans believe the alleged shootout was a cover-up for a planned assassination.
President Salinas appealed yesterday for calm after holding an emergency Cabinet meeting. He called Colosio's death ``an offense against all Mexicans ... who have always rejected violence as the way to solve our problems.''
At this writing, no decision has been made as to who will take up the PRI banner. The presidential candidate named by the PRI is seen by many Mexicans as the de facto appointment of the next president. It could be days before a new candidate is chosen, political analysts say.
``One would hope there would be a pause, while things calm down, and the leaders in the PRI will take time to make this important decision,'' says Jaime Gonzales Graf, director of the Mexican Institute of Political Studies, a Mexico City private think tank.
Other presidential candidates have temporarily halted their campaigns to attend the funeral of Colosio. But no one is recommending that the Aug. 21 elections be postponed.
It's not clear how the Mexican financial markets - which have plummeted and soared lately - will react. The day before Colosio's death, the Mexican stock market shot up 5.4 percent on the news that PRI party rival Manuel Camacho Solis was taking himself out of contention.
Colosio's campaign had gotten off to a sluggish start as Mr. Camacho's profile and popularity rose as the government's peace negotiator in the Chiapas conflict. It was Camacho, not Colosio, who was front-page news, and he upset some PRI party members by supporting the rebel call for greater democracy in Mexico.
There was rampant speculation that Camacho might challenge Colosio or leave the PRI and run for president. But under intense pressure from his party, only one day before Colosio's death, Camacho removed any doubt about his intentions.
``Between seeking a candidacy for the presidency of the republic, and the contribution I could make to the peace process in Chiapas, I choose peace,'' Camacho said Tuesday.
The former mayor of Mexico City, Camacho ``has a big team within the PRI and could pull a big chunk of the Federal District. There's no other obvious strong candidate,'' says John Bailey, a Mexico specialist at Georgetown University.
But some analysts say he may be too obvious a choice. Precisely because of the brouhaha of recent weeks, Camacho may be passed over again for a less-controversial candidate, who may have more success in unifying the party.
Among those on the original short list before Colosio was selected, were Emilio Gamboa Patron, secretary of communication and transport; Treasury Secretary Pedro Aspe Armella; Ernesto Zedillo Ponce de Leon, Colosio's campaign manager and a former education secretary; and Emilio Lozoya Thalmann, secretary of energy, mines, and state firms.