The politics of urban land use frustrate even the best intentions. A number of cities have made strong political commitments to increasing their local housing supply in the face of a crisis of affordability and availability in urban housing. However decisions to engage in “up-zoning”or increasing the areas in which new housing can be built, are often offset by even more “down-zoning” laws that decrease the ability of residents in a designated area to build new housing as-of-right. The result is that housing availability does not increase by anywhere near the amount that elected officials promised In this Article, we argue that the difficulty cities face in increasing local housing supply is a result of the seriatim nature of local land use decisions. Because each down-zoning decision has only a small effect on the housing supply, citywide forces spend little political capital fighting them, leaving the field to neighborhood groups who care deeply. Further, because down-zoning decisions are made in advance of any proposed new development, the most active interest group in favor of new housing-developers-takes a pass on lobbying. The result is an uneven playing field that favors downzoning.