Due to a remarkable convergence of criticisms from both the right and the left, zoning is under more sustained attack than at any time in the last seventy-five years. A consensus is building that zoning is what ails America. Simultaneously, the traditional justifications for zoning like separating incompatible uses, have become increasingly anachronistic in an age of mixed-use development and a desire for vibrant, dynamic places. This Article offers an updated defense of zoning, and in particular density regulations. Today, local governments deploy zon- ing not primarily to keep industry (or apartment buildings) out of residential neighborhoods, but to preserve community stability by regulating the pace of change, protect property values, and allocate the costs of development and growth. Zoning serves important but unappreciated pur- poses that must be included in the ledger when evaluating zoning reform.