He'd help look after his teenage sister, watching to make sure she wasn't spending too much time with the boys who chase after her. And he'd be able to hang out with his younger brother, maybe playing catch like the other brothers he sees in the park here.

Most of the time, Mr. Ortega, 22, tries not to indulge himself in this way. He just goes about his day. He tries to avoid dwelling too much on his loved ones, who remain in a small town near Puebla, in southern Mexico.

But something happened early last year to cause these dreams, and since then it has been hard to rein himself in. What happened was that Mr. Ortega heard about President Bush's new immigration plan.

"I thought it would make everything better, much better," he said one recent afternoon, heading to the restaurant where he works as a dishwasher. "We got so excited. I was making plans to save money to bring everyone here fast."

What he caught wind of, specifically, was something called the guest worker plan, which the administration has fitfully discussed with the Mexican government over the past year, and which the news media have episodically reported on - but which remains mostly in the realm of theoretical possibility.

Very little is known about it - just that it would match employers to potential employees, who would be allowed to stay in the United States for up to three years but would then have to return home. Critics on both sides seem to agree that the plan could very quickly attract thousands of low-wage Latin American immigrants.

Beyond that, there are only questions. Mr. Ortega, for his part, wonders what it would mean for people like himself, who immigrated illegally but have been living here for years. Would the sudden influx of new immigrants shut him and others out of jobs? Would the newcomers be able to bring their family members with them? If he signed on among their number, to work here legally for several years, would he still be able to apply for citizenship later? Would the working years he has already put in here count for anything?

The last time such a state of anxiety and hopeful confusion manifested itself among Hispanic immigrants was in the mid-1980's, just before the Immigration Reform and Control Act of 1986 provided amnesty for an estimated 2.7 million people, most of them Mexican.

But since the amnesty, there has been no major change in status for illegal immigrants, and critics today see the Bush administration proposal, at least so far, as unresponsive to the fate of those millions who have moved here to work, generating Social Security and Medicare tax revenue estimated in the billions of dollars - but unable to benefit from that revenue because of their undocumented status.

"There's no way people who are already here are going to go back," said Robin A. Bikkal, a White Plains lawyer who has helped hundreds of immigrants gain citizenship over the last two decades. "For them, it's an absolutely worthless plan. There's no incentive to go back."

IN the 2000 census, the Hispanic population of Westchester was put at 144,000; in 1990 the figure was 96,500. Today, immigration lawyers and other experts in the county believe that the number could be nearly double the 2000 census estimate.

Latino immigrants - especially from Mexico, but also from Ecuador, Guatemala and elsewhere - have settled everywhere from Yonkers to Peekskill and Mount Kisco to Mamaroneck. In 1990 they made up more than 50 percent of the population in a small swath of Port Chester. A decade later there were 10 such neighborhoods, in parts of Yonkers, Ossining and Eastchester, according to census data.

The men continue to follow the established pattern of taking day-laborer jobs in construction and landscaping; the women are usually domestic workers. (At the county level, there are no clear statistics showing the percentage of those immigrants in low-wage jobs. But national studies indicate that immigrants make up about 11 percent of the population and 20 percent of the low-wage work force.)

"The evidence is overwhelming that there has been a dramatic shift in the last several years," said Dean Hubbard, who holds the Joanne Woodward chair in Public Policy at Sarah Lawrence College. "We are living in an era of capital mobility and labor mobility. The capital goes with cheap labor and the labor goes where the job is."

In Westchester, he said, this has meant that several town councils have been forced to grapple with the presence of increasing numbers of day laborers. Debates on the subject have in certain cases engendered bitterness. Officials in Mount Kisco and Port Chester have supported the creation of indoor hiring sites where workers can be sheltered while waiting for the day's job, but other governments have been reluctant to approve such sites. Some say such plans are too costly; others argue that they only encourage a greater influx of undocumented workers.

But because day laborers' larger numbers are already a fact of life in the county, sophisticated support groups now exist to help them. Lawyers like Ms. Bikkal and organizations like the Westchester Hispanic Coalition in White Plains offer counseling, tackle immigration questions and advise workers how to collect unpaid wages - essentially navigating the system for a large group of the otherwise disenfranchised.

LABORERS these days work for around $10 an hour. In the busy spring months, they find as much as six full days of work a week. At other times, they can go for several weeks without finding a single job, as several said they did this winter. Some say they worry about seeking a job without a Social Security number, but others say they would most likely have to work two or three minimum-wage jobs to make the same amount of money.

Every morning around 7:30, as many as 300 men begin to gather along a quarter-mile stretch of Yonkers Avenue, just off the Cross County Parkway. There, they wait for landscapers, contractors, even private homeowners who may be looking for help for a few days.

"You don't know what you can count on," said Juan Macedo, 50, who immigrated from Guerrero, Mexico, 12 years ago. In recent years, Mr. Macedo has organized Obreros Unidos, or Workers United, which is asking Yonkers City Hall to create a hiring site. "Of course it is better to find permanent work," he said, "but that is not usually possible."

Mr. Macedo shares a two-bedroom apartment in Yonkers with three other men, a typical arrangement for many of the men who live in Westchester while their families remain in their home countries. After paying his $300 rent, Mr. Macedo says, he typically sends up to $300 a month back to his wife and three teenage sons.

"If they have a better education, they can do better than this," he said of his sons, then pointed to a blister in the middle of his right palm. "They are in school and they study very hard all the time."

Because Mr. Macedo has a green card, he is able to return to Mexico once a year, usually around Christmas, when work is slow anyway. Farther down the street, an undocumented worker who gave only his first name, Eliseo, said he had not been back to Guatemala to see his family since he arrived here in 2002.

Such a journey could take several weeks. If Eliseo hired coyotes, as the people who help others cross the border illegally are known, it could cost thousands of dollars.

"Of course I miss them," he said of his loved ones, looking down at his feet. "But what can I do? There is no choice about this."

It is not uncommon for undocumented men such as Eliseo and Mr. Ortega to live just below the radar. Both say they rarely venture from the neighborhoods they live in, mostly spending time with cousins and others they may know from their hometowns. Neither has a bank account, a driver's license or even a permanent home address. And above all, they both said, they try not to complain or cause trouble.

"I know if I do one thing wrong, they will kick me out of here," Mr. Ortega said. "I don't want to do anything to get sent away. If that happens, everyone will be in trouble. I can't get kicked out."

The ultimate goal is citizenship. Typically, being sponsored by a family member who already has it is the quickest and easiest way for immigrants to start the legal process.

For those without close relatives already living here, finding an employer to sponsor them is the next best option. To do so, employers must prove that they have enough money to pay workers' salaries and that there is no American citizen able, willing or available to do the job they require.

Single men in their 20's and 30's far outnumber female immigrants living in Westchester. The women who do live here are often even further removed from the wider society than the men, experts say.

"The men you see everywhere on the streets, doing landscaping, the masonry work, those kinds of things," account for about 80 percent of her clients, Ms. Bikkal said. "The women are in jobs behind closed doors, which makes it even more difficult."

At the start of each case, Ms. Bikkal said, she routinely asks the men if they have a serious girlfriend.

"Does she have papers? No. Are you living with her? Yes," she says, without pausing for a breath. "O.K., time to get married."

"That's the best way to help the women, to get them the same rights and benefits that the man is getting," she said. "Otherwise, they can sit and wait forever."

WHILE politicians and advocates in Washington argue about details of the still-theoretical guest worker plan, immigrants in Westchester chew over what little they know, with a little hope and a lot of confusion. Many rely on Spanish-language television news, which has been fascinated with the subject for months now. They glean information and trade it. Often, in the retelling, the information becomes misleading.

After he heard about the plan, Mr. Macedo said, he immediately thought of bringing his family to the States, only to have his hopes dashed upon learning that such move could only be temporary.

"We want to live here as a family, but I don't want them to come illegally," he said. "That's no way to live."

Mr. Ortega, too, started with the wishful assumption that the proposal could mean nearly automatic amnesty for him and his family. He calculated how much it would cost to get flights for his mother and siblings. Soon afterward, he started to look for affordable apartments suitable for the whole family.

"At first, nobody could stop talking about it," said Graciela Heymann, executive director of the Hispanic Coalition. "Anytime there's anything mentioned about immigration, there is either a lot of hope or fear."

Like experts nationally, she and Ms. Bikkal say there is almost no doubt that if the worker plan was approved, many more immigrants will come to American shores, pushed on by the promise of economic security.

All the more reason for workers already here to be concerned: the plan could theoretically force them to register in order to get work. They would then, presumably, be asked to return to their home countries.

A survey conducted earlier this year by the Pew Hispanic Center indicated that more than half of Mexican immigrants would be willing to return after receiving a three-year temporary work visa, as the president's plan calls for. But Mr. Ortega, like dozens of others interviewed, said there was little chance that he would ever willingly give up the chance to earn money in the United States and send some back to his family in Puebla.

From the viewpoint of advocates in the field, Ms. Heymann said, another major problem with the guest-worker plan is the impact of coping with a new wave of inexperienced immigrants every three years.

"We want to import labor," she said, "but we get people. People bring with them all kinds of issues. They have to learn the language, they have to learn the schools, they have to learn health care and they have to learn their rights. All of that takes time, so if you have one group constantly moving in and out, that's never going to happen."

As an example of a concept that is tough for new immigrants to accept, she cited labor rights that many were too fearful or suspicious to exercise. For years, she has worked to convince workers in low-wage jobs that they can enlist the government's help in recovering unpaid wages or fixing unsafe working conditions. Under state and federal laws, all are entitled to pursue claims for back wages, regardless of immigration status.

Michael Higgins, an assistant attorney general who works with the state's day laborer task force, says that in recent years more men have been willing to press their cases. He handled about 100 cases in the New York City region last year and expects the number to grow this year.

"Typically, I'll see guys who've worked for someone for two or three days and then been told, 'Sorry, I can't pay you now,' " Mr. Higgins said. Usually, a worker will go to a community-based organization first, and caseworkers there will contact the federal Department of Labor or the attorney general's office. "It's usually not that much money, and most employers turn around and pay pretty quickly," he said.

At the Westchester office of the Labor Department, Susan Rivera deals with similar cases of back pay for many minimum-wage earners, mainly people in the food service industry. Last year, she said, she was able to get final paychecks in 59 cases, for a total of $29,090.55 in wages.

MARIA ELENA BUSTOS remembers harboring hopes of a better life when she first came to the United States in the early 1990's. Though she had relatives from Puebla elsewhere in New York City as well as in Los Angeles, she decided to settle in Yonkers, after hearing that housing was cheaper and jobs were more plentiful. She worked in a hotel for several years, but quit when the early morning hours became too difficult to manage with young children.

Now, with a son in his 20's and a daughter finishing high school, Ms. Bustos has two jobs cleaning office buildings -one in Stamford, Conn., and the other in White Plains. Both pay about $8 an hour, giving Ms. Bustos about $300 in take-home pay each week.

With the Bee-Line bus strike dragging on, Ms. Bustos has spent recent weeks worrying about how to get from her home to at least one of her jobs. Usually, her son drives her there and she finds a ride back with a friend, but on several occasions she has had to pay as much as $20 to get to White Plains.

She says she considers herself lucky: "My work is for my children. I want them to be here and get a good education and be able to succeed. That's what everyone has done, right? It was the same for the Italians who came here, right? They worked hard and then the children benefited."

Copyright 2005 The New York Times Company