The states, the US Supreme Court and presidential candidates are debating the consequences of illegal immigration — at a time when it's on the decline. Agricultural interests in Arizona, Georgia and Alabama are claiming a shortage of workers from Mexico. The Pew Hispanic Center has recently reported that, "The net migration flow from Mexico to the United States has stopped — and may have reversed." Hard liners claim that will change when the recession is over, and the dispute continues about the undocumented workers who are already here. But, large waves of immigrants have shaped American since the beginning. We debate the possible causes and potential policy impacts. Meantime, should it change our thinking if a massive wave of immigration has come to an end?