In 2005, 3 percent of the world’s residents left their country of birth or citizenship for a year or more. These migrants include persons in all legal statuses whose reason for being abroad range from study to work to settlement. Most industrial countries have organizations that advocate no borders at one extreme and no immigrants at the other. These extremes have hardened, and each faction seems to prefer the status quo to a compromise that can be enacted into law, which may explain the persistence of the status quo.The U.S. had 37 million foreign-born residents in 2007, totaling 12.3 percent of the U.S. population and almost 20 percent of the world’s international migrants. The Senate in May–June 2007 debated and failed to approve the “co...