Few legal metaphors enjoy more prominence than that of a legal issue “percolating” through the lower courts until the Supreme Court is ready to resolve it. Just two Terms ago, for example, the Court declined to answer a question presented in Box v. Planned Parenthood of Indiana & Kentucky, Inc., reasoning that further percolation would aid it in developing the scope of constitutional protections for a woman’s right to choose. In Trump v. Hawaii, Justice Clarence Thomas wrote to express dismay that nationwide injunctions are “preventing legal questions from percolating through the federal courts.” Similarly, Justice Neil Gorsuch wrote in Department of Homeland Security v. New York that nationwide relief undermines “the airing of competing views that aids [the] Court’s own decisionmaking process,” a view shared by many critics of the lower courts’ use of nationwide injunctions in recent years. A common presumption is that percolation is valuable.

This Article questions that presumption. Its thesis is that, at best, percolation’s benefits will outweigh its costs under limited and contingent conditions—conditions not likely to replicate themselves across a broad range of cases. In advancing that thesis, the Article makes four contributions to the literature on federal court practice and procedure. First, as a historical matter, it shows that interest in percolation’s value is a relative latecomer to the jurisprudential scene. Second, as an analytical matter, it distinguishes between informational and institutional accounts of percolation’s value. Informational accounts highlight percolation’s potential to provide useful information to enhance the Court’s decisionmaking as to a particular legal issue. Institutional accounts, by contrast, see the percolation process as beneficial to the effective functioning of the federal court system as a whole. With this important but largely unrecognized distinction in mind, the Article makes a third contribution by showing that both accounts are subject to significant limitations. In particular, both the informational and institutional accounts of percolation’s value are highly issue-dependent and context-specific. Therefore, as a prescriptive matter, this Article makes a fourth contribution by highlighting a set of practices that the federal courts or Congress might adopt in response to the limited nature of percolation’s informational and institutional benefits.

* Michael Coenen (michael.coenen@shu.edu) is a Professor of Law, Seton Hall University Law School. Seth Davis (sethdavis@berkeley.edu) is a Professor of Law, University of California, Berkeley School of Law. We would like to thank the participants in workshops at Cardozo Law School, Harvard Law School, and the University of South Carolina School of Law for their helpful comments.