In the broadest terms, states with a long history of assimilating foreign-born migrants are largely defending the ideal of the United States as a "nation of immigrants," legal or illegal. Meanwhile, states that have before been largely isolated from immigration patterns are now taking a "the law is the law" approach.
The result is a pattern that roughly fits the red-blue divide with the South and inner West opposed by the Northeast and West Coast. But the patchwork of immigration policy could have a silver lining: As states struggle with the issue, their efforts could provide starting points for more meaningful federal reform.
"In the very short run, it is a good thing for states and lawmakers to go on record about where they are on immigration policy – from both sides – because it clarifies what steps need to be taken at the federal level to achieve higher standards of immigration law enforcement and compliance," says Jessica Vaughan, policy director for the Center for Immigration Studies, which advocates stronger immigration enforcement.
The regional immigration divide is in large part based on dramatic shifts in migration patterns, boosted by America's troubles in controlling its southern border. Outside of the so-called Big Six immigration states – California, New York, Illinois, Florida, Texas, and New Jersey – the immigrant population has increased 200 percent during the past 15 years. In seven states, more than half of those immigrants are undocumented. In another 17, about 40 percent are undocumented.