Homeland Security shifts policy to target employers with illegal workers

The shift in emphasis will be outlined in revamped field guidelines issued to agents of Homeland Security's Immigration and Customs Enforcement division as early as this week, according to several officials familiar with the change in policy. It is in keeping with comments that President Barack Obama made during last year's campaign, when he said past enforcement efforts have failed because they focused on illegal immigrants rather than the companies that hire them.

"There is a supply side and a demand side," said one Homeland Security official. "Like other law-enforcement philosophies, there is a belief that by focusing more on the demand side, you cut off the supply."

Another Homeland Security official said the changes come as a result of a broad review of all Immigration and border security programs and policies that Napolitano launched in her first days in office.