Jerry Markon and Anne Kornblut offer "Justice Department considers suing Arizona to block immigration law" (link): Officials in the Obama administration are urging the extraordinary step of suing Arizona over its new immigration law, and the Justice Department is considering such an action to block the legislation from taking effect, government officials said Wednesday. A key legal ground being considered, officials said, is the doctrine of "preemption" -- arguing that the state's law illegally intrudes on immigration enforcement, which is a federal responsibility... The prospect of federal...