In Immigrants: Your Country Needs Them, Phillipe Legrain makes an economic argument for open borders. While he describes an ideal, the reality is that the United States will not implement an open border policy anytime soon. In recent years, Congress has been unable to reach a consensus regarding immigration policy reform. While Congress is stalled on the issue, there are twelve million undocumented immigrants living in the United States and that number is increasing. In response to the lack of a federal movement on the issue, many states, cities, and towns have begun passing their own laws regulating the rights of illegal immigrants. This book review examines the legality of these laws in light of recent challenges brought in federal courts and concludes that during this period of federal legislative transition, it is the responsibility of the courts to invalidate those local laws that violate the preemption doctrine. Immigration and naturalization are exclusively federal legal territory, and laws passed on the local level must not be permitted to thwart federal progress in creating and enforcing a uniform national policy.