Eighty miles of the Mexican border is already fenced off, with 14 more being completed near San Diego. Immigration hardliners, including Republican Congressman Duncan Hunter of San Diego, want to finish the job with a fence that runs all the way from the Pacific Ocean to the Gulf of Mexico. It would feature barbed wire and ditches, creating a wide barrier illuminated with stadium lighting and monitored by cameras and motion detectors. The cost to fence the remaining 1900 miles comes with a price tag of $2 million a mile, or $4 billion to $8 billion. It's either the ultimate solution to illegal immigration or the ultimate fantasy. Would it stop the flow of humanity or just slow it down? What about cracking down on employers? What does President Bush want to do? We speak with immigration reformers, growers, the border patrol and experts in Mexican-American political relations.