It took four months for Rafael, a Brooklyn construction worker, to return to his Sunset Park apartment after being nabbed in a major immigration sweep at Newark International Airport.

He could have been back in days. “It’s already a custom,” Rafael said in Spanish, lounging under a collection of Virgin Mary figurines in the room he shares with three other illegal immigrants from Mexico. “One goes and comes and comes and goes.”

As human smugglers build a growing pipeline between small towns in Mexico and New York, the city is discovering what Southwest border states like California and Texas already know: The illegal flow over the 1,950-mile U.S.-Mexico border is relentless.

New York’s Mexican community, the city’s fastest-growing major immigrant group, quadrupled between 1990 and 2000, to 122,550, according to official statistics provided by the city. The actual numbers are likely even higher. Roughly 80% of the state’s Mexican population is undocumented, according to demographer Jeffrey Passel of the Pew Hispanic Center. He estimated that the 2004 population stood at 180,000 illegal immigrants out of 225,000 Mexicans in the state.

Most Mexican illegal immigrants pay a “coyote,” or smuggler, to sneak them across the border, community leaders say. The going rate is $2,000. Once in America, it’s a train, bus, van, car, or plane ride to their final destination.

Enforcement efforts, both at the border and locally, are failing to stem the flow, they say.

“Everybody who is deported, they come back,” the executive director of Asociacion Tepeyac, Joel Magellan, said. The community group works with Mexican immigrants in New York, including more than a dozen families of individuals caught in the April 8 sweep at Newark. “They want to work, to survive, because there they don’t have employment in their country.”

Rafael was deported as part of a groundbreaking interdiction carried out far from the border. Acting on a tip that came in last April, U.S. Customs and Border Police officers met the 222 passengers of a Continental Airlines flight from Los Angeles International Airport upon their arrival at Newark. Before the passengers could leave the airport, the officers demanded proof of immigration status. Eighty-eight Latin American passengers, most of them from Mexico, were placed in immigration detention.

Most signed voluntary removal orders. After up to two weeks in area jails and detention centers, they were placed on flights, paid for by the U.S., and sent back to their respective countries.

Five of the passengers were expected to spend the night at Rafael’s one bedroom apartment in Sunset Park, a landing pad for many newly arrived Mexicans. Less than a year after the Newark interdiction, two are back.

“People are going to keep coming,” said Efraim, a grocery night janitor who shares a room with Rafael. “They’re coming here to work, and if they don’t have the money they borrow it. Some need to come back because they have to repay the money.” Efraim, 25, lost the $1,950 he paid for his sister’s passage. She is still in Mexico, but Efraim says without hesitation that he’s certain most of those who were caught in the sweep have returned. “Like it’s their home,” he says.

After he was dropped on the Mexican side of the border last year, Rafael, 39, said he paid for an 18-hour bus ride to Mexico City and then another five hour ride to his rural town in the state of Puebla. There, he returned to the apple and pear farm and his wife and four daughters, whom he supports with the $500 a week he earns in New York.

He would rather live in Mexico, he says, but he needs the American dollars to provide a better future for his children. Rafael was inclined to return immediately, but his brothers, who funded his trip and lost $2,000 when he was turned back, needed the four months to earn his next passage.

Even though experts say an increasing number of minors are crossing the border, Rafael said it was too dangerous to bring his daughters. But when his brothers had gathered the $2,000, this time to be paid on arrival, he was ready. He called the coyotes he knew at the border town of Mexicali and made the return trip by bus and plane. After one night in a hotel, he and three other men set off on a 17-day journey to Brooklyn.

When Rafael first came to New York, seven years and four trips ago, it took just three hours to cross the border near Tijuana. Patrol officers since have closed off many border towns, forcing many immigrants to take a dangerous, sometimes deadly, trip through the desert. Rafael walked for five days, eating only tortillas and energy vitamins, sleeping sitting up in order to be ready at all times, and carrying all his belonging for the voyage in a disposable plastic bag.

Even after arriving at a highway near Tucson, Ariz., they still needed to be on guard.

After the Newark raid and subsequent similar sweeps there and at other airports, the Department of Homeland Security in July launched an anti-smuggling initiative at LAX. The agency, which subsumed the Immigration and Naturalization Services nearly two years ago, posted federal officers in visible sites at the airport in an effort to prevent smugglers from using it as a hub.

Apparently, it was enough to make Rafael’s smuggler avoid the airport. He traveled over land to Los Angeles and San Francisco before flying to Philadelphia via Chicago. From there, a van took Rafael, the three other men, and their coyote to Brooklyn, where his apartment, and his job as a roofer, were waiting.

Even Department of Homeland Security officials say actions like the Newark operation can do little to stop the flow.

“It’s just a fact that individuals do attempt to reenter the country,” a spokesman for Immigration and Customs Enforcement, Manny Van Pelt, said.

But, Mr. Van Pelt said, actions like the one at Newark Airport do serve as a deterrent in some cases. “The concern we have is that a person has to realize if they do reenter the country the stakes are much higher in the law-enforcement realm,” he said.

In the case of immigrants like Rafael, he said, reentry after removal is a criminal violation and if caught he could be charged with a felony. “We’re an orderly nation and we’re a nation of laws,” Mr. Van Pelt said. “And this country’s immigration system, as generous as it is, is not to be exploited.”

Last year, hoping to find a job washing plates in New York, a step up from cleaning houses in Mexico, Efraim’s sister, Maria, asked her brother to pay her way, with the understanding she would repay him after she established herself. When she exited the airplane at Newark on the April morning, she thought her border-crossing ordeal was over.

“They said the worst had passed,” Maria said, speaking in Spanish. “We had arrived. I thought I would walk the fastest we could and grab a taxi and a few minutes from there was everything: the house of my brother. This was the worst, that I felt I had it in my hands and they took it away from at that moment.”

She said she knows she broke the law, but she felt like she did it for a just cause: to better her situation.

Speaking from her home in Puebla, Mexico, Maria said that after having her arms, waist, and legs shackled, she never wants to come back to America.

Another brother, though, is planning to make the trip and join Efraim in New York. Rafael said he intends to visit Mexico once he is done repaying his brothers. After all, his family is there.

“They close one part, but then there is another side,” he said, following a 12-hour shift laying roof. “People will continue to come.”