Why do some local governments build more homes during housing shortages while others hold back? I argue that partisan incentives, shaped by geography and connectivity, condition these responses. In dense city centers, limited space and stable demographics constrain how much partisanship matters. In well-connected suburban belts, conservative mayors may limit multi-family construction to avoid an influx of left-leaning urbanites, whereas left-wing leaders embrace such developments to broaden their electoral base. In peripheral municipalities less connected to the city, fears of a changing electorate are weaker, reducing partisan polarization over housing supply. Using a novel, nationwide panel of German municipalities (1990–2021) and a close-elections regression discontinuity design, I identify the causal impact of partisan control on housing supply conditional on geography and connectivity. Linking these outcomes to individual-level panel data reveals how mover demographics reinforce or undermine partisan equilibria. The findings highlight that partisan considerations, not just zoning or NIMBYism, shape housing supply and contribute to persistent affordability challenges.