Debating The Impact Of An Immigration Crackdown

"Next year Congress is expected to again take up immigration reform, something it tried, but failed, to pass in 2006 and 2007.  The collapse of those efforts prompted a number of cities and states to adopt their own regulations aimed at driving out [unauthorized] immigrants. But years later, it can be hard to tell just how much impact they had." - Jennifer Ludden, NPR, Dec. 26, 2012.