DECISION IN MEXICO : Winner Inherits Thorny Colosio Case : Probe: For many, the muddled investigation of the March assassination symbolizes profound doubts about rule of law.

As Ernesto Zedillo claims victory in Mexico’s presidential election, he moves toward a challenge that could prove the ultimate test of his promises for change: the Colosio case.

Although Mexico’s next president will enter a dramatically altered political landscape bristling with difficult tasks, perhaps none is as politically and personally delicate as the unresolved assassination of ruling party candidate Luis Donaldo Colosio.

Colosio’s killing at a Tijuana campaign rally in March catapulted Zedillo, the slain candidate’s campaign manager, from technocratic obscurity to the pinnacle of power.

With the election race in full swing in July, angry Mexicans rejected the government’s conclusion that the alleged killer, Mario Aburto Martinez, acted alone. A new special prosecutor was appointed to probe allegations of a conspiracy, notably the increasing accusations of a plot involving hard-line leaders of Zedillo’s Institutional Revolutionary Party (PRI) and powerful drug cartels.

Zedillo inherits both a muddled investigation and a weary citizenry left cynical by generalized lawlessness and a string of unsolved murders linked to drug corruption.

For many Mexicans--according to Mexican officials, journalists, human rights activists and other analysts--the Colosio case has come to symbolize profound doubts about the rule of law.

“The question is whether the Mexican judiciary system works,” said Jorge Mancillas, a UCLA professor and adviser to the alleged gunman’s family, which accuses the government of involvement in a plot. “The Colosio case is a litmus test of whether any of the major political parties understand the issue or just inherit a system of government based on patronage and corruption.”

Many conspiracy theorists share Mancillas’ fear that the crime will simply fade into memory and myth, becoming Mexico’s version of the assassination of President John F. Kennedy.

“Zedillo isn’t going to do anything,” scoffed a young official in Baja California, a state run by the opposition National Action Party. “He has too many debts and connections. The main suspects are the ‘dinosaurs’ (old-guard politicians), who are very powerful in his own party.”

But there is another school of thought: that either Zedillo or lame-duck President Carlos Salinas de Gortari, who will rule until December, could make the case top priority in a bold, risky attempt to demonstrate true reform.

Recalling how Salinas sought to legitimize his questionable victory in 1988 with attacks on high-level corruption, one analyst said Zedillo would benefit from an aggressive investigation of the Colosio case.

“Even if the intellectual authors turn out to be people close to the system, this could become a strategy to purge the PRI and symbolize a new era,” said Tonatiuh Lopez Guillen, a political scientist at the College of the Northern Border in Tijuana.

The assassination was not a prominent theme in Zedillo’s campaign. But he declared on several occasions that he and his party wanted justice done.

Regardless, the law enforcement and political obstacles remain formidable. Critics say that former special prosecutor Miguel Montes Garcia came up with thin evidence, neglected potential leads and lurched from a conspiracy theory--he filed charges against five alleged plotters--back to the lone gunman scenario. The result: confusion and suspicion among the public.

Moreover, the trail has grown cold after five months. It seems more difficult than ever to establish whether Aburto’s mysterious conduct and self-proclaimed political connections were indicative of a plot or of a deluded lone assassin.

“Resolving the case necessitates reconstructing the chain of events,” said Gerardo Albarran de Alba, a political reporter for Proceso, a respected national weekly. “That will be difficult. . . . Even if the opposition won, it would be difficult to break the blockage of information within the police apparatus, to totally renovate the judicial system.”

The main development recently has been the emergence of a potential new witness, Eduardo Valle Espinosa, a former top aide in the attorney general’s office who headed an elite unit investigating powerful drug lords. A colorful, tough-talking former student leader and journalist known as “The Owl,” Valle quit his post in May and denounced the corruption that he says has turned Mexico into a “narco-democracy.”

More recently, Valle has offered to testify about his suspicions that the assassination was related to infiltration of the Colosio campaign by drug-trafficking interests; he has also implicated two former police commanders who worked as Colosio aides, and named top government officials with alleged drug ties as well. Valle told journalists that he tried to warn Colosio of the dangers shortly before the candidate’s death. Valle has moved to Washington for his safety.

Investigators are preparing to take his testimony at an as-yet undesignated Mexican consulate in the United States, spokesman Miguel Angel Sanchez de Armas said Monday. Since the appointment in July of special prosecutor Olga Islas de Gonzalez Mariscal, authorities have taken 64 statements from previous witnesses and new ones, he said.

“Nothing has emerged that has enough relevance to change the direction of the initial investigation,” Sanchez said.

Although Valle’s allegations remain uncorroborated, his statements, coming from a knowledgeable former law enforcement official, add credibility to assertions that Colosio fell victim to the fearsome mix of drugs and politics; and a high-ranking official of the Baja state government said in an interview that, before the assassination, he learned that men with purported criminal connections were part of the Colosio campaign.

“I was very surprised to see the kind of people who were around Colosio,” said the Baja official, who suspects a conspiracy involving some of the most powerful politicians in Mexico.

But pursuing the “narco-politics” thesis would pose considerable danger if the case remains open when Zedillo takes office. It could bring him into conflict with PRI “dinosaurs,” who were instrumental in his apparent victory.

Experts question whether the president would have the strength or desire for this clash amid the multiple challenges of resolving the conflict with Indian rebels in Chiapas, negotiating with powerful opposition parties and putting together a viable government.

Similarly, although Salinas’ image would benefit from an investigative bombshell before he steps down, he may not have the power to strike such a blow. “It’s hard to foresee serious progress coming from an initiative led by the present government before Dec. 1,” when it goes out of power, Mancillas said.

So Zedillo could end up ordering investigators to determine conclusively whether or not Aburto acted alone, then trying to persuade the Mexican people of the correctness of the outcome. At stake would be the credibility of the justice system as well as who killed Colosio.

“Certainly, Zedillo like no one else will feel pressure to resolve the case with the truth,” said Albarran of Proceso. He added that, if the narco-politics thesis is valid, “Zedillo is doubly obligated--because the next president will have to fight drug trafficking to the point that is politically and humanly possible in order to heal the democratic life of this country.”