Do citizens really want these jobs?

Scott Joyal says that if it weren't for illegal immigrants taking jobs that could have been his - first as a car washer or waiter, later in carpentry and construction - he would have had a lot easier time surviving financially over the past 10 years. The San Jose carpenter says he knows dozens of his colleagues who, like him, are also struggling to pay rent and keep food in the refrigerator because of competition from immigration.

It's a view that goes to one of the core questions raised by President Bush's proposal to let millions of illegal workers become legal "guest workers": Would they be stealing jobs that American citizens want and need?

Bush says no.

He calls it a "basic fact of life and economics" that some jobs being generated in America are ones citizens don't want to fill.

Yet that premise is controversial - in a slow job market in which millions are looking for work - and to many economists it is misleading. Many citizens will, and do, work side by side with immigrants who may be illegal in industries from meatpacking to hotels and landscaping. "Those workers are competing with US workers," says Dean Baker, an economist at the Center for Economic and Policy Research. "It's simply not true that US workers won't take these jobs." But many, he concedes, won't take them at the going wage.

In the view of many economists, the question is less one of stealing jobs than of altering the balance in labor market. The influx of immigrants, legal and illegal, adds to the supply of low-cost labor and puts downward pressure on pay. The upside, for the US economy, is lower consumer prices and, in some cases, keeping some production at home that might otherwise shift overseas.

For example, what if instead of recognizing "guest workers" the government took a policy of aggressively weeding out illegal immigrants? The resulting upward pressure on wages might push some jobs in, say, meatpacking or agriculture out of the country. But in other cases, it might prod businesses to increase wages, expand the use of automation (such as in harvesting), and to pass higher costs along to consumers.

Gauging the precise impact of immigrants, especially the illegal ones for whom the guest worker program is designed, is tricky. And employer groups and groups favoring limits on immigration can come up with very different conclusions. In one 1997 study the National Research Council found that immigration depresses wages modestly for many lower-income workers - by perhaps 5 percent over 15 years.

To many on the ground, however, the impact feels large. Construction is one industry where Baker says pay scales have been hit the immigrant influx.

"I'm not against [immigrants]," says Mr. Joyal, the San Jose carpenter. "It just makes it difficult for native-born Americans to get jobs when undocumented aliens are lined up to get them first."

Since 1993, he says he has been turned down by carwashes, schools seeking janitors, restaurants, and hosts of construction jobs because immigrants got there first or underbid him.

Landscaping is another industry transformed by immigrant labor, even in states as far from the border as North Carolina.

Keith Martin, who owns a Raleigh-area landscape business, says the native-born Americans he encounters don't want to do the type of jobs he routinely gives to immigrants.

"Through my experience, Americans don't want to do this type of work, no matter what you pay them," says Mr. Martin, who runs a small shop with a trailer of mowers and hedge trimmers.

This doesn't prompt him to support Bush's guest worker idea, but it's the current reality of a business that involves laboring in the oppressive heat of Dixie, trimming curbs of suburban ranch houses and keeping the flower beds at local high-tech firms looking healthy.

In Bush's plan, illegal immigrants already in the US could apply for a three-year work permit, which would be renewable at least once. By giving legal status to millions already working in the fringes of the US economy, observers say, Bush's plan is to help ease labor shortages, improve working conditions, and stabilize wages paid to previously illegal immigrants.

But with the president scheduled to meet Monday with Mexican President Vicente Fox, the merits of the plan are a topic of hot debate.

"This is really a far bigger issue than just who gets low income jobs in immigration and border states," says Mark Krikorian of the Center for Immigration Studies. "There are no numerical limits on these guest workers or what sector of the economy the jobs apply to. If employers can bypass American workers and not have to offer better wages and conditions ... the consequences to the American workplace could impact everyone."

According to the Center for Immigration Studies, there are more than 5.5 million working immigrants in America - legal and illegal - who lack high school education. Eighteen percent are in agriculture, 18 percent in construction, 16 percent in retail, 23 percent in manufacturing, 7 in business services/repair and 6 percent in personal services from maids to limo drivers.

"When we have 18 million Americans who can't find full-time jobs, it seems ludicrous to even be considering a program to import more foreign workers," says Rosemary Jencks of Numbers USA, an immigration reduction organization.

Kate Bronfenbrenner, a labor expert at Cornell University, says you can't draw a one-to-one comparison between the estimated 7 million illegal immigrants and the ranks of the US unemployed.

Some jobs categories are growing fast, she says, and they are often low-paying ones such as nurses' aides and housecleaners. "It's not true that Americans aren't working in them. There are just are plenty of those jobs to go around."

She worries, however, that Bush's plan tilts power heavily to employers, since the guest workers are not granted permanent residency. "Bush has established a program that gives employers the opportunity to exploit immigrant workers to an even greater degree."

• Patrik Jonsson and Mark Trumbull contributed to this report from Raliegh and Boston.