Four trucks pulled up outside the Casa Hogar Elim orphanage on Children's Day, one of Mexico's most popular holidays. Guadalupe Carmona de Gonzalez, who runs the children's home, said men unloaded thousands of dollars worth of chicken, rice and milk, and boxes of brand-new dolls and toys.

They also brought four big sheet cakes decorated with Winnie the Pooh and the Little Mermaid and a note drawn in icing: "For the children at Casa Hogar, from your friend Osiel Cardenas Guillen."

Carmona said the children squealed in delight. But authorities in Mexico and the United States expressed dismay at the thought of Cardenas, one of Mexico's most notorious drug traffickers, ordering shipments of goodies from his cell in Mexico's main maximum-security prison.

In at least three other places along the U.S.-Mexico border on Children's Day, April 30, children received truckloads of bicycles, dolls and other toys from Cardenas, who has been incarcerated since his arrest last year in a spectacular shootout between his bodyguards and Mexican soldiers. Cardenas, 37, a former police officer, also sent thousands of dollars for relief supplies to the border city of Piedras Negras in April after floods that killed more than 30 people.

Officials said Mexican drug dealers have long been silent benefactors, building roads and churches and passing out cash or drugs to win support -- or silence -- in the communities where they work. But officials said Cardenas 's public donations appear to be the first of their kind.

"Those toys represent the suffering of many people, the destruction of many families," said Jose Luis Santiago Vasconcelos, Mexico's top organized crime prosecutor.

Officials in both Mexico and the United States say that grass-roots support is a key reason the Mexican cartels continue to operate, despite what U.S. officials call a "golden era" of cooperation between law enforcement agencies in the two countries and a series of high - profile arrests.

Larry Holifield, chief of the Drug Enforcement Administration's Mexico and Central American office, called Mexican trafficking groups "the most powerful in the world" in a recent speech in Panama and estimated their trade at $65 billion a year.

In interviews in three cities on the 225-mile stretch of the border closest to the Gulf of Mexico, the home territory of Cardenas's Gulf Cartel, local officials and citizens said drug traffickers continued to overwhelm law enforcement. Since January 2003, there have been 108 drug-related deaths in this area, from Nuevo Laredo to Matamoros, the Gulf Coast city south of Brownsville, Tex. The vast majority of the killings are unsolved, according to the Center for Border Studies and Human Rights in Reynosa.

"We're never going to be as powerful as they are," said Ronaldo Rivas Carrillo, municipal police chief in Valle Hermoso, a city of 60,000 people just south of Matamoros, which also received a truckload of toys from Cardenas.

Rivas said Cardenas's power comes not just from the cartel's superior weapons and collusion with corrupt police and officials, but also from his campaign to win hearts and minds among the poor. Much of the cartel's support comes from young people, who see the cartels as exciting, rich and a ticket out of poverty, Rivas added.

"I compare it to the war in Northern Ireland, where when they tried to find the guerrillas, the little children would go and warn them," he said. "Here it's the same thing. The groups have penetrated very deeply into society, and they are absorbing the youth."

Rivas and other officials said cartels received help from locals, such as shoeshine boys or taxi drivers, who accepted money or drugs in exchange for informing the traffickers about police or army activity. They said others looked the other way, whether out of gratitude or fear.

In Reynosa, residents said a man who left no name or telephone number paid $1,000 in cash to rent a private hall for a Children's Day party. Private buses then took 300 poor children to the hall, where four trucks with no license plates arrived filled with expensive toys.

Law enforcement officials said Cardenas might also be trying to build sympathy as the court considers trafficking charges against him. While many of those who received gifts weren't immediately told that they were from Cardenas, local reporters were told and Cardenas's gifts were top news for days in newspapers and television stations along the border.

"Individuals like Osiel Cardenas want to be seen as Robin Hood," said Michael Vigil, who was head of the DEA's San Diego office until his retirement in May. "That's the way they play it; they manipulate public sentiment."

Raymundo Ramos, head of a human rights organization in Nuevo Laredo, said he thought Cardenas was trying to create the kind of popular following that the late Colombian drug lord Pablo Escobar cultivated in his home city of Medellin, where he built hundreds of homes for the poor. Ramos said Cardenas wanted the poor to see him as more generous than a government that has done little to improve education, health and other basic services. "The message he's sending to the masses is, 'I'm the good one and the government is the bad one,' " Ramos said. "He's really taking advantage of the absence of power left by the federal government."

On the morning of Children's Day, cars with loudspeakers trawled the poor neighborhoods of Valle Hermoso, playing a recording inviting children to a big party with free gifts at the Spanish Casino, a private hall near the center of downtown.

Francisca Montalvo Gomez, 39, heard the cars as they passed on the dirt road in front of her tiny wooden house. Two of her daughters, Jaley and Vanessa, ran over to the hall and found hundreds of children already lined up. The girls said they waited in line for about 30 minutes, and each received a doll from the clowns who were passing out gifts, juice and candy. Standing in their front yard three weeks later, they still giggled as one of their gifts, a baby doll, answered its little cell phone and sang a well-known pop song.

Montalvo said she had not known who was handing out the gifts, figuring it was probably the local government or a church group, until the local press revealed the next day that it was Cardenas. "Maybe he regrets his crimes," she said. "He must be a good person if he's doing things to help poor people."

Around the corner, Karen Lopez played with a large "Magnum Fighters" robot she received at the party, after spending two hours in line with her mother, Abigail Lopez. She stored the robot carefully in its box; her mother said it probably cost nearly $20, and that Karen , 4, had never had such an expensive toy. She took out her robot and laughed in delight as it walked across a tabletop, buzzing and flashing its lights.

Sergio Torres Martinez, a local official in Valle Hermoso, said the municipal government could not compete with Cardenas, whose organization is believed to run several billion dollars worth of cocaine into Texas every year. Torres said the local government had thrown parties for children but could not afford expensive presents. "It's discouraging when a private citizen, a criminal, can make the work of city hall look so small," he said.

Torres said the government tried to counter the drug traffickers' heroic image among young people by teaching a class in local elementary schools, stressing the values of family life and good citizenship and the dangers of drugs. He said the city had put as much money as it could into youth sports programs.

"Since we can't fight the narcos directly, we have to fight other ways," he said.

The cartels are also fighting for public support in creative ways.

Carmona, the director of the Casa Hogar Elim, said she had asked the local Nuevo Laredo government for 17 years to pave the dirt street in front of the children's home . After failed attempts by the city last year, she said some men, who were accompanied by local reporters, did the paving work, saying they had been sent by Cardenas.

City officials, apparently unhappy that Cardenas was paving the road, sent their own employees, who dug up all the work his men had done, leaving the road a mud pit for another month, Carmona said. They are now paving it again .

Carmona said that the families of many of the children in her home had been destroyed by drugs and their parents were in jail or dead. But she said she saw no irony accepting toys from a major drug dealer. As an evangelical Christian, she said, she preaches forgiveness and teaches the children right from wrong.

"The first thing I tell the children is to pray to God for him, that he's not a hero," she said.

When reporters came to interview Carmona about Cardenas, she said she looked into the television cameras and spoke directly to him: "If you're watching, thank you. Christ loves you and we are praying for you."

Jordan reported from Mexico City.