Why has there been an immigrant surge?

The Bush administration, which is vowing to crack down on U.S. companies that hire illegal workers, virtually abandoned such employer sanctions before it began pushing to overhaul U.S. immigration laws last year, government statistics show.

Between 1999 and 2003, work-site enforcement operations were scaled back 95 percent by the Immigration and Naturalization Service, which subsequently was merged into the Homeland Security Department. The number of employers prosecuted for unlawfully employing immigrants dropped from 182 in 1999 to four in 2003, and fines collected declined from $3.6 million to $212,000, according to federal statistics.

In 1999, the United States initiated fines against 417 companies. In 2004, it issued fine notices to three.