Many Americans now can't live without them - but sometimes they can't live with them.
A growing number of Americans believe that immigrants are a burden to the country, taking jobs and housing and creating strains on the health care system. Many people also worry about the cultural impact of the expanding number of newcomers in the U.S.
Ubiquitous as they are in the public debate over immigration, day laborers are only one part of a diverse population of unauthorized migrants
The population of unauthorized migrants in the U.S. is between 11.5 million and 12 million, according to a new report from the Pew Hispanic Center.