Housing affordability is one of the most pressing issues facing California today. In the intense public debate over how to make housing affordable, the role of new supply is a key point of contention. This debate continues despite robust empirical evidence demonstrating that supply constraints -- low-density zoning chief among them -- are a core cause of increasing housing costs. Many California residents resist new housing development, especially in their own neighborhoods. This white paper provides background on the opposition to new housing construction and a set of policy recommendations for the state government to address this resistance. I first describe how limiting new construction makes all housing less affordable, exacerbates spatial inequalities, and harms the state's economic productivity and environment. I then discuss the varied motivations for opposing more intensive land use, and highlight the way the complexity of the housing market confuses public debates over this topic. In the fourth section, I list various tactics used to block housing projects and demonstrate just how many veto points there are in our current system. I conclude by presenting several proposals for reform that have potential to reduce the power of local opposition to new housing. The state government should take action in at least four areas -- enforcing and enhancing existing laws, pushing local planning agencies to represent more people more equally, providing information for public discussion, and developing ways to make planning decisions at a metropolitan, not neighborhood scale.