Book excerpt: Sanctuary cities, or localities where officials are prohibited from inquiring into immigration status, have become a part of the broader debate on undocumented immigration in the United States. Despite the increasing amount of coverage sanctuary policies receive, the American public knows little about these policies. In this book, Loren Collingwood and Benjamin Gonzalez O'Brien delve into the history, media coverage, effects, and public opinion on these sanctuary policies in the hope of helping readers reach an informed decision regarding them.