Book excerpt: "For those who seek to improve health through policy change, this book is intended to be your companion. It is written by practitioners, elected officials, and other policymakers who have firsthand experience with the complex dynamics of policymaking through their professional careers. Its chapters share perspectives on the power of policy from the federal, state, and local levels; demonstrate several evidence-based policy packages developed by leading public health organizations; provide perspectives not only on legislative policy but on the roles of litigation and regulation; and reveal the existing threats to using policy to impact health. We hope that this book will inspire current and future public health practitioners and pMolicymakers to use policy to achieve optimal and equitable health for all"--