Our setup offers a rare opportunity to examine in a real-world setting the prominent puzzle of whether behavioral phenomena can be responsible for flypaper effects in public finance. We study municipal income tax rates in Portugal and find an ideology-specific tax policy response to a change of the default tax rate which, from a neoclassical perspective, should not alter the decision problem of local policymakers. While being at odds with standard economic theory, the quasi-experimental evidence reported in this paper is consistent with an explanation based on mental accounting and classical ideological preferences regarding taxation.