Twenty years ago, Sinaloa state’s moneyed elite wouldn’t give Jesus Vizcarra the time of day. His murky past and rumored ties to major drug traffickers kept him out of the top social clubs and business associations.

Today the same power brokers who once shunned him are Vizcarra’s enthusiastic backers as he emerges as the solid favorite to become governor.

To critics, Vizcarra’s election on Sunday would be the culmination of a steady penetration by narcotics traffickers into Mexican political power. Vizcarra, backed by the omnipotent Institutional Revolutionary Party, or PRI, counters that he has done nothing wrong. He has not been charged with any crime, and the federal attorney general’s office said last week it was not investigating any case involving Vizcarra.

But he has neither answered pointed questions about his past, nor been able to explain away compromising evidence and a quickly amassed fortune.

Sunday’s elections in 14 states have highlighted the corrosive influence drug gangs and their money have on Mexican politics and races for important offices.

Deep infiltration (and intimidation) of the political class by organized crime has hamstrung the government of President Felipe Calderon in its nationwide campaign to battle powerful drug cartels, an offensive now in its fourth violent year. With rare exception, authorities have left corrupt politicians untouched and failed to adequately monitor dirty money in election campaigns.

On Monday, assassins killed Tamaulipas state gubernatorial candidate Rodolfo Torre in a highway ambush, the highest-ranking candidate slain since a presidential hopeful in 1994. Usually, however, the damage is more subtle, yet insidiously effective.

“Narco-politics is the greatest threat to Mexico’s incipient democracy,” said federal congressman Manuel Clouthier Carrillo, who represents Sinaloa for the National Action Party, or PAN. “If federal authorities don’t fight it now, the damage will be irreversible.”

In Sinaloa, drug tycoons like Ismael “El Mayo” Zambada channel untraceable millions into the hands of politicians who then use the cash not only to line their own pockets but to pay for vote-garnering public works projects and buy elections, according to politicians, law enforcement sources and experts in drug trafficking. In return, Zambada and his compatriots can be assured that local and state police and other agencies are at their disposal.

Sinaloa is the most entrenched example of narco-politics, and the phenomenon is spreading across Mexico.

In Ciudad Juarez, where fighting among drug gangs has made the city Mexico’s deadliest, the leading candidate for mayor is fending off allegations of ties to traffickers.

The candidate, Hector Murguia of the PRI, who served as mayor from 2004 to 2007, has faced questions over what he knew of the activities of his police director, who in 2008 was arrested and convicted in Texas on drug smuggling and bribery charges.

Murguia, in an interview with The Times, strongly denied any relations to traffickers and said he had no idea whether the former police commander, Saulo Reyes, was involved in illicit activities before leaving office. But a senior American law enforcement official told The Times that the PRI candidate has attracted U.S. scrutiny because of his alleged past cooperation with the Juarez cartel.

Murguia’s main rival, Cesar Jauregui of the PAN, says Murguia has drug ties and cannot be trusted to ensure public safety in a city where rival traffickers are engaged in open warfare. Murguia dismisses Jauregui as a “loudmouth” and says he will sue for defamation after the election.

In neither Ciudad Juarez nor in Sinaloa do such allegations seem to hurt the candidates.

“People don’t look at the ethical or moral origins [of a candidate] but at the services they can receive,” said Lauro Melendrez, owner of a chain of pharmacies and one of numerous prominent Sinaloa businessmen supporting Vizcarra. “We don’t have the luxury to demand pie-in-the-sky ethical values. A society in crisis is less demanding.”

Fertile Sinaloa is largely controlled by interconnected entrepreneurs, politicians and marijuana and cocaine traffickers, tied together by family relations and business dealings — a mafioso cabal, in the words of Clouthier. They bought huge tracts of land, built fancy housing projects, and diversified into cattle and purebred horses.

Some even set up charitable foundations. Many have kept their hands clean by using intermediaries, and thanks to exclusively cash transactions, there is little paper trail.

Vizcarra came from a poor rural family, one of 10 children of a father who sold chickens for a living, in the heart of the isolated Golden Triangle, a drug smugglers’ paradise along the Sierra Madre.

Vizcarra’s mother has acknowledged, and birth documents made available to The Times show, that they are related to Ines Calderon Quintero, a founding father of the drug cartel that dominates Sinaloa. Calderon was killed by police in 1988.

After moving to Culiacan in the 1970s, Vizcarra started out with a few cows, then received cash from friends and relatives whom he won’t identify. Within a few years he had built Grupo Viz, a meat production and exportation conglomerate estimated by businessmen to be worth $800 million today.

As his wealth grew, he was welcomed into the posh Roma and Sinaloa gentlemen’s clubs and the main business associations as he cut lucrative deals in real estate and other ventures. Successive Sinaloa governors from the PRI juggernaut took him under their wing.

Soon, he was hosting dinners for Mexican presidents at his ranches, and in 2007 he was elected mayor of Culiacan.

In December, the newspaper Reforma published a photograph that showed Vizcarra attending an outdoor religious ceremony with Zambada and other traffickers or their relatives at a Zambada family ranch. Reforma said the photo was about 20 years old and was taken at a Mass for the Virgin of Guadalupe.

Vizcarra downplayed the image, offering the improbable explanation that he was merely there to buy cattle.

Since then, one persistent rumor has dogged Vizcarra: Zambada agreed to Vizcarra’s request that he serve as his first son’s godfather. That would make Zambada and Vizcarra compadres, an extremely important and cherished relationship in Mexican culture.

Vizcarra has refused to say whether that’s true. Residents of Sinaloa report having heard the son boast of the relationship. Reporters who sought the baptismal records at the church where the ceremony took place found the relevant pages had been torn from the register.

Last month at the final candidates’ debate of the gubernatorial campaign, Vizcarra’s rival, Mario Lopez Valdez, stood at a lectern and looked squarely into the television camera. “Jesus Vizcarra,” he said, “are you or are you not the compadre of El Mayo Zambada?”

Vizcarra ignored the question, reverting instead to a stock line he repeats frequently.

“I have never done anything against the law,” he said, adding that the accusations against him are part of a “dirty war.” “My work is transparent.”

Outside the debate, the crowd that had gathered chanted, “He should answer! He should answer!”

Lopez Valdez, widely known by the acronym of his names, Malova, is the owner of a chain of hardware stores and a federal senator who had been a member of the PRI but broke with the group. He is the candidate of an odd-bedfellows alliance of the leftist Revolutionary Democratic Party and the conservative PAN, President Calderon’s party.

The tones of the two candidates’ campaigns are striking in their contrast.

Vizcarra hardly mentions violence or drug trafficking. Instead, he repeats the mantra that he will “help the people” with jobs, paved roads, free diapers. His defenders praise him for an efficiently run city administration and his undying support for business.

Malova warns darkly of continued corruption and drug-fueled bloodshed. One of his campaign TV spots showed residents of Sinaloa blindfolded and gagged, surrounded by scenes of destruction.

“We are not safe in our streets. We are not safe in our homes,” Malova said in an interview in the well-guarded house that serves as his campaign headquarters in Culiacan.

Vizcarra declined requests for an interview.

At a rally cleverly staged around Mexico’s World Cup 2-0 win over France, Vizcarra cheered on potential voters and gave away soccer jerseys and balls.

Maria de Lourdes Clouthier, 63, no relation to the congressman, stood in line with her daughter and granddaughter waiting for the freebies. She said she planned to vote for Vizcarra because he’s “done a lot” for the city.

Asked about the reports of his ties to Zambada, Clouthier tsk-tsked: “Oh, there’s no reason to get into that. No, no, no. It is not important.”

wilkinson@latimes.com

ken.ellingwood

@latimes.com

Richard A. Serrano of the Washington bureau contributed to this report.