We study the relationship between housing supply and political partisanship in US cities using an expanded database of mayoral elections combined with local housing permits since 1980. The endogeneity of which party holds the mayoral office is addressed via a regression discontinuity design that relies on closely contested races between Republicans and Democrats. Across a variety of election samples and econometric specifications, we find that partisanship does not have a statistically or economically significant effect on the supply of total, single- or multifamily housing unit permits despite recent increases in measured partisanship. This suggests that solutions to limitations on housing supply will not be dependent upon the political party in power at the local level.