A recent decision of the Oregon Tax Court suggests that it may be premature to dismiss the challenging questions raised by the retroactive application of Wayfair as entirely hypothetical. Accordingly, after providing an overview of the case law governing retroactive application of Supreme Court state tax decisions repudiating preexisting constitutional doctrine, we examine the Oregon Tax Court’s opinion in Global Hookah Distributors Inc. v. Department of Revenue, which addressed the question whether Wayfair applied retroactively to the state’s tobacco products tax.

States are rekindling the trend of broad constitutional amendments that require supermajority approval to create or increase taxes. This trend may inadvertently harm states' already precarious fiscal footing, particularly with several new imminent expenditure demands. States can minimize negative economic consequences, however, through proper supermajority requirement design.

This article makes three contributions. First, it examines broad constitutional tax supermajority requirements' history, asserted justifications, and effectiveness. This examination concludes that the motivations underlying the first and second supermajority waves differ importantly from those underlying the possible third wave. Recognizing this novel motivation-signaling low-tax competitive advantage-allows this article to present optimal supermajority provision design principles.

Second, this article investigates several new sources that can generate immense tax revenue for states, but that will likely be obstructed by tax supermajority provisions if not designed properly. This article also identifies several expenditure demands that are unlikely to be satisfied without new or increased taxes.

Finally, this article presents tax supermajority requirement design principles that achieve a strong low-tax signaling function while allowing flexibility to maintain a low-tax competitive advantage. Fundamentally, the constitutional tax supermajority requirement should expressly encompass personal income tax, business taxes, and fees, while excluding transaction taxes. If a state decides to pursue a broad tax supermajority requirement, these design principles will best position a state to attract businesses and wealthy individuals while also achieving fiscal stability.