Anita Krishnakumar

Ambiguity has long played a central role in statutory interpretation—serving as the trigger for judicial resort to extratextual materials or any one of a slew of interpretive canons.  The rule of lenity, the avoidance canon, legislative history, and even the erstwhile Chevron deference regime all turn (or turned) on a threshold determination that the statute at issue is ambiguous.  In proportion to ambiguity’s centrality, scholars have felled forests theorizing about ambiguity and judges have argued for decades over how much ambiguity is sufficient to trigger the application of particular canons. ¹

In The End of Ambiguity (in Statutory Interpretation), Abbe Gluck draws on clues from Supreme Court opinions, the Justices’ comments at oral argument, and their extra-judicial writing to argue that ambiguity’s reign is over—and that its demise is a sign of a larger shift in power from Congress to Article III courts.  The End of Ambiguity is a tour de force of an article, full of illuminating insights and observations about how and why ambiguity is on the decline and what ambiguity’s demise teaches about the current (and future) state of statutory interpretation on the Roberts Court.

To begin, the article highlights three trends, or “moves,” that together have combined to undermine ambiguity’s pivotal role in statutory interpretation.

First, Gluck notes the modern Court’s growing frustration with the manipulability of ambiguity thresholds.  Justice Kavanaugh, as Gluck points out, wrote an entire essay criticizing ambiguity thresholds as arbitrary and advocating that courts should “reduce the number of canons of construction that depend on an initial finding of ambiguity.”  Gluck also makes the important point that Chevron deference was felled in large part because of the modern Court’s frustration with its ambiguity threshold.

Second, Gluck identifies a “growing jurisprudential discomfort” with many of the substantive canons that turn on ambiguity triggers—highlighting recent oral argument comments by Justices Gorsuch, Kavanaugh, and Kagan that question the source and legitimacy of such canons.²

Third, Gluck notes that the current Court “lacks the inferiority complex of its predecessors,” who were ever-mindful of the countermajoritarian difficulty and sought to interpret statutes as “faithful agents” of the legislature.  By contrast, Gluck observes that the modern Court’s second-generation-textualists, led by Justices Barrett and Gorsuch, have sought to redefine the Court’s role in statutory cases as serving as an agent of the people, faithful to the law as it would be understood by ordinary citizens.  Gluck argues that this ordinary citizen focus “increases skepticism about ambiguity” because ambiguity “is by nature a deferential construct” that instructs courts to resort to external norms only when Congress leaves ambiguities in statutes, thereby delegating or creating interpretive space for courts to step into.  This last point is especially powerful and crucial to Gluck’s larger conclusion that the modern Court is engaged in a power grab that wrests control over statutory meaning away from the legislature.  It also highlights how recent power grabs the Court has made in the administrative law context have strong parallels in the statutory interpretation context—beyond and on top of the overruling of Chevron.  Overall, Gluck does an excellent job of connecting the dots between all of the interpretive trends she identifies and demonstrates persuasively how they have converged to lay a foundation for minimizing and even eliminating the role that ambiguity plays in modern statutory interpretation.

The article goes on to highlight numerous examples of how ambiguity’s role in triggering specific canons is evolving—and inching towards elimination.  These include, inter alia, ongoing debates about whether a finding of ambiguity is a necessary trigger for the major questions doctrine,³ whether “grievous ambiguity” or merely “reasonable doubt” is necessary to trigger the rule of lenity,⁴ and whether a threshold determination of ambiguity is necessary before applying the avoidance canon.

Perhaps most troubling, Gluck shines a spotlight on where the modern Court may be going by highlighting the implications of an extended oral argument conversation between Justices Alito, Kagan, Kavanaugh, and Barrett in the 2022 case, Ysleta Del Sur Pueblo v. Texas.  In that oral argument, Justice Kavanaugh suggested that the substantive canons of construction fall into two buckets: (1) a bucket of ambiguity-dependent canons that require a threshold finding of ambiguity and (2) a bucket of plain statement canons that “usually reflect some constitutional or quasi-constitutional value, due process, extraterritorial structure” or the like.  Gluck posits that this may be the beginning of an unprecedented judicial attempt to rank the canons—and to disfavor those that are ambiguity-dependent.  Time will tell whether and how such a ranking of substantive canons plays out, but Gluck makes a persuasive case that the Court is moving in this direction.

The article is full of numerous other valuable insights and documentation of various canons’ state of play, but I will leave those to the reader to discover.  In short, The End of Ambiguity is a must-read article for anyone seeking to understand the contemporary Roberts Court’s approach to statutory interpretation.

1. See, e.g., Ward Farnsworth, Dustin F. Guzior & Anup Malani, Ambiguity About Ambiguity: An Empirical Inquiry into Legal Interpretation 2 J. Legal Analysis 257, 271 (2010).
2. See Transcript of Oral Argument at 62-63, Ysleta del Sur Pueblo v. Texas, 596 U.S. 685 (2022) (No. 20-493) (Justice Kavanaugh); id. at 59-60 (Justice Kagan); Transcript of Oral Argument at 23-25, Barrett v. United States, (No. 24-5774) (argued Oct. 7, 2025) (Justice Gorsuch).
3. See Learning Resources, Inc. v. Trump, 607 U.S. 229, 242-43, 277-79 (2026) (opposing views articulated by Justices Roberts and Gorsuch).
4. See Wooden v. United States, 595 U.S. 360, 370, 388 (2022) (debate between Justices Kavanaugh and Gorsuch).