Do Laws Have a Constitutional Shelf Life

"[T]imes change."1 Those were the words of Justice Kennedy when the Supreme Court heard oral argument in Shelby County v. Holder,2 the 2013 decision that invalidated a key section of the Voting Rights Act (VRA).3 The Court found the law's coverage formula-which determined if a state or local government must obtain permission before changing voting laws-to be outdated and unconstitutional.4 The formula was designed to cover jurisdictions most vulnerable to race discrimination.5 The Chief Justice, writing for the majority, explained that this part of the law (which was written in 1965, revised in 1982, and reauthorized without change by Congress in 20066) was based on "decades-old data," "eradicated practices," and needed to be "updated."7All parties agreed the law was "rational" when written, but the Court reasoned that it now ignores developments in racial conditions such that it has grown to be irrational and bears "no logical relation to the present day."8 Stale factual assumptions in the formula rendered the law unconstitutional today even though it was constitutional in the past.9 In the Chief Justice's words, "the Act imposes current burdens and must be justified by current needs."10This reason for invalidating a law is puzzling. Adjusting for changed circumstances when interpreting the Constitution is nothing new-indeed, that argument is basically as old as the Constitution itself. John Marshall wrote that a Constitution is "intended to endure for ages to come, and, consequently , to be adapted to the various crises of human affairs."11 Oliver Wendell Holmes said the Constitution must be interpreted in light of "what this country' has become."12But the Shelby County Court answered a question different from the one asked by these jurists. Much ink has been spilled on the theoretical question in constitutional law: when do changed facts (or a changed "understanding of the facts"13) alter the way we interpret the Constitution?14 When does the meaning of the Fourteenth Amendment, for example, change to forbid racially segregated schools or bans on gay marriage? The question I will address in this Article is a different one: whether, and under what circumstances, a statute that was constitutional at the time of enactment might become unconstitutional over time-not because the prevailing understanding of the Constitution has changed but simply because things in the world around us have changed.15The question answered in Shelby County was not whether Congress had constitutional power to pass the Voting Rights Act.16 It was not even about whether our understanding of the scope of that pow er had changed from 1965 to 2013. The question was whether the passage of time and changed circumstances created a distinct reason to invalidate the law-rendering it obsolete and effectively expired.The concept I use as shorthand for this question is the prospect of a "constitutional shelf life."17 The goal of this Article is to track this idea of a shelf life across various aspects of constitutional law-, to demonstrate that the issue arises in far more contexts than one might anticipate, and then to consider w hether it is a concept capable of principled application.Although others have previously wrestled with this question from time to time,18 it is one that remains "radically under-theorized."19 Moreover, it is a question that is growing in significance today as two things change: (1) judges find themselves with new tools to examine the factual premise of a law,20 and (2) the Supreme Court is embarked on "a widespread empirical turn" where its opinions now rest more explicitly on factual claims about the way the world works.21 But, as I will demonstrate, even though facts matter a great deal to constitutional doctrine, the Supreme Court has not given clear guidance about what to do when those facts change over time.Consider, by way of comparison to Shelby County, the 1989 decision of Michael H. …