Millions of illegal-immigrant U.S. workers are vulnerable to exploitation because the federal government fails to protect them, advocacy groups said in a petition to an international human-rights body.

1. Do illegal immigrants really take jobs from American workers?

Yes, they do.

There is no doubt that to many native-born U.S. workers illegal immigrants represent competition, plain and simple. The economic platitude that “immigrants take jobs no American would do” – expressed by both President Bush and Mexican President Vicente Fox – is only partly true. Many Americans wait tables, wash dishes, mop floors and lay bricks for a living. In fact, more than 80 percent of jobs in the farming, cleaning, construction and food preparation sectors – jobs usually associated with illegal immigrants – are held by native-born Americans.

Out of 473 job classifications, as assigned by the Center for Immigration Studies, just four are made up predominately by illegal immigrants: stucco masons, tailors, produce sorters and beauty salon workers.

Which is a fancy way of saying there aren’t many jobs that American workers won’t do.