Passed Over for Nomination, Mexico City Mayor Quits : Politics: Manuel Camacho had been a top contender for ruling party’s presidential candidacy. Some fear he may join opposition.

This capital’s appointed mayor, Manuel Camacho, once considered a front-runner in next year’s presidential race, resigned Monday, the day after rival Luis Donaldo Colosio’s designation as candidate of Mexico’s ruling party.

Camacho said he was leaving the highly sought-after mayor’s post to accept an unspecified federal government appointment. Government sources later said he has been named foreign relations secretary.

Camacho had been considered the contender most likely to promote political reform, which has lagged behind economic change here.

The resignation--made before the official announcement of his new post--is as close as a member of the highly disciplined Institutional Revolutionary Party (PRI) has come to expressing disappointment in the presidential selection process since Cuauhtemoc Cardenas left the party five years ago and launched an independent candidacy. Cardenas has since formed an opposition party that has pressed for democratic reforms and clean elections, often embarrassing the government.

“I aspired to be the Institutional Revolutionary Party’s presidential candidate,” Camacho told an impromptu news conference for City Hall reporters. “I have considered my options and, among them, what in my opinion is best for our democratic life. . . . I do not believe that the way to advance democracy is by polarizing political life.”

While some see in Camacho’s move a potential major split of the ruling party, others caution that he is just one man--albeit one with a considerable following.

“It’s not a major division of the party,” said Adrian Lajous, a longtime political observer who writes a column for the pro-government newspaper Excelsior. “Someone lost out who thought he should win, and now he’s very disappointed.

“He’s a bad loser,” Lajous said, repeating a sentiment echoed by others.

But government critics said the resignation of the 47-year-old reform-minded mayor, with a reputation as his party’s conciliator, could be serious.

There is widespread agreement that a Camacho defection to the opposition is a possibility. Such a move would further fracture a ruling party already riven by the 1988 leftist split Cardenas initiated.

“The danger now is that Camacho could join the opposition,” Lajous said. “He has to be treated with silk gloves.”

At the very least, political analyst Jorge Castaneda said, the action shows how costly the outdated presidential selection process of the outgoing leader choosing his successor has become.

“This was the most closed destape (unveiling) in 50 years,” Castaneda charged.

In the past, while the sitting president has always had the final word, the nomination has been preceded by public discussion and private consultation with business and labor leaders. That trend toward the appearance of a greater opening culminated six years ago in a televised debate among leading contenders for the PRI nomination.

But in interviews Sunday after Colosio was named, veteran labor leader Fidel Velazquez and Senate Majority Leader Emilio Gonzalez appeared as surprised by the announcement as anyone else, indicating President Carlos Salinas de Gortari had done little consulting.

After Colosio’s nomination was announced, the third top contender, Finance Minister Pedro Aspe, immediately congratulated the winner, closely followed by the rest of Mexico’s leading politicians.

Camacho, however, never appeared among the well-wishers crowding to Colosio’s door in what Mexicans call the buffalo stampede. Late Sunday night, reporters were still waiting--in vain--outside the mayor’s house for a reaction.

He said Monday that he had reached Colosio and “wished him, for the good of the country and our party, success in his candidacy.”

Like Colosio, Camacho is a close friend of Salinas’. Unlike the candidate, he has an independent political following. Colosio is considered far more likely to continue Salinas’ free-market economic programs, which include an austerity program that often falls on the poorest Mexicans and a selloff of government-owned companies that sometimes appears to benefit the richest.

“I would say Camacho was judged to be untrustworthy,” Lajous said. “There was some concern that he would not carry on the programs of economic reform that Salinas started.” Further, his specialty--compromise--sometimes appeared to party insiders as something more akin to giving away the store.

“My commitment is to the nation,” Camacho said, “to its institutions, to the responsible conduct of the economy, to a policy that reflects the interest of the majority and not only interest groups.”

Meanwhile, Colosio resigned, as expected, from his Cabinet position as head of the Social Development Ministry to launch his campaign. He was replaced, also as expected, by Carlos Rojas, who directly manages the politically popular anti-poverty program called Solidarity.

Foreign Relations Secretary Fernando Solana will become education secretary, and Education Secretary Ernesto Zedillo will be Colosio’s campaign manager, the government source said.

Camacho will be replaced as mayor by Manuel Aguilera, Mexico City chairman of the PRI, he said.