Written to accompany and respond to Erwin Chemerinsky's essay in the same symposium, this essay argues that each substantive defense of the mandate is subject to doubt. While Congress could have avoided the issue by using its taxing power, it chose not to do so. Congress has power to regulate commerce among the several States, but that might not extend to every individual decision involving economic considerations -- walking rather than taking the bus, stargazing rather than renting movies, or carrying a gun in a school zone rather than hiring private bodyguards. Even the necessary-and-proper power, the strongest ground for the mandate, may stop short of letting Congress claim extraordinary powers to fix the problems created by its exercise of ordinary ones.

Because the mandate's opponents can find some support in existing doctrines, a decision striking down the mandate needn't be a drastic break from past practice. By contrast, a decision upholding the mandate would raise serious questions about the limits of Congress's powers. To many, these questions offer good reasons for doubting whether existing doctrine gets it right -- reasons having more to do with constitutional theory than political preference.

Drawing from the theory of collective action federalism that he recently articulated with Robert Cooter, the author argues that the Commerce Clause is best understood in light of the collective action problems that the nation faced under the Articles of Confederation, when Congress lacked the power to regulate interstate commerce. One way a collective action problem arises is when people benefit from collective action regardless of whether they contribute to it. To over-come failures to participate in collective action whose effects spill across state borders, the clauses of Article I, Section 8 authorize Congress to require various kinds of private action.

This authorization includes requiring financially able individuals to obtain health insurance or pay a fee instead of free riding on benevolence by shifting costs to others (cost shifting) or waiting to obtain insurance until they are already ill (adverse selection). To the extent such free riders are deemed inactive, their inactivity is a problem, not a reason why Congress is powerless to offer a particularly effective solution. Congress can offer such a solution when spillover effects impede the ability of the states to solve the cost shifting and adverse selection problems on their own. Theoretical reasoning and empirical evidence suggest that the states are not well situated to solve the two problems that the minimum coverage provision aims to address.