E-commerce has altered the relationship between consumers, businesses, and U.S. states. E-retailers are not required to collect sales tax from their customers, thus depriving fiscally insecure states of tax revenue, and providing a competitive advantage for eretailers, like Amazon Inc., in their struggle for market share with brick-and-mortar stores, like Walmart. Attempts at e-commerce sales tax policy by state legislators and brick-and-mortar lobbyists failed until 2008 when New York successfully passed legislation. A subsequent wave of legislation ensued, and between 2008 and 2012, e-commerce sales tax legislation left committee in fourteen states, each experiencing various levels of success. Existing explanatory efforts have not fully accounted for the combinatorial effect of political-institutional structure and market contestation in U.S. state-level policy creation, as well as the likelihood of multiple pathways to passage. Embracing this framework, I use fuzzy set Qualitative Comparative Analysis (fsQCA) to uncover three sufficient pathways for successful passage of e-commerce sales tax policy. Two paths highlight the confluence of large retailer pressure and a conductive political-institutional structure facing fiscal stress, while the third path reflects political-institutional forces. These findings corroborate, as well as build upon, our knowledge of fiscal sociology, policy domains, and corporate power in American politics.