National restrictions on trade and immigration are the most salient illustrations of the current protectionist moment, but cities have played their part too, taxing foreign investors in local real estate and imposing second or vacant home taxes that indirectly burden foreign investment. Although these protectionist property taxes are new, they draw from an old well of suspicion about foreign ownership. We provide economic and historical context for the recent wave of protectionist property taxes and evaluate their legality under U.S. law. We conclude that taxes on second or vacant homes would likely survive constitutional challenge but facially protectionist property taxes probably would not. We then assess the policy merits of these taxes using an economic framework that highlights how law affects housing risk. We show that foreign real estate investment can reduce the riskiness of local housing markets, so that even if a city can get away with enacting a protectionist property tax, it is not typically a good idea. Government spending can better achieve policy goals such as affordable housing and neighborhood stability without running afoul of constitutional prohibitions.