The Sixth Edition offers a comprehensive and up-to-date introduction to the vital field of legislation and regulation. It addresses efforts by President Trump to curtail the powers of the administrative state, and new Supreme Court decisions reviewing challenges to these efforts under the Constitution and the Administrative Procedure Act. In addition, the Sixth Edition expands its celebrated treatment of statutory interpretation, examining recent debates among textualists, legal process advocates, and pragmatists about future directions of interpretation in a post-Scalia era. The new edition also creates separate chapters addressed to intrinsic interpretive doctrines (dictionaries and canons) and extrinsic doctrines (the common law, legislative background, and other statutes), with each chapter highlighting recent decisions by the Supreme Court. Finally, the Sixth Edition includes important updates on the law of the legislative process-notably developments addressed to equality in representation; racial and national origin vote dilution; political gerrymandering; and bribery of public officials. The Sixth Edition makes a uniquely rich contribution to the field: it is perfect for 1L Legislation and Legislation-Regulation (LegReg) courses, and it remains the go-to book for upper level courses.

The 2023 Supplement incorporates important developments that have arisen or deepened since the publication of the sixth edition of the Casebook in 2020. These developments include a Problem on Students for Fair Admissions v. Harvard and a Note on reconciliation and the filibuster in Chapter 1; Supreme Court decisions addressed to the law of representational structures in Chapter 2 (Brnovich v. Democratic National Committee, Allen v. Milligan, and Moore v. Harper), to anti-corruption in Chapter 3 (Kelly v. United States, Ciminelli v. United States, and Percoco v. United States), and to theories of statutory interpretation in Chapter 5 (Bostock v. Clayton County and Niz-Chavez v. Garland); extended Notes on post-Dobbs ballot initiatives in Chapter 4 and original public meaning and a newer textualism in Chapter 5; Supreme Court decisions addressing structural canons, the rule of lenity, and constitutional avoidance in Chapter Six (Dubin v. United States, Wooden v. United States, and United States v. Hansen); and Supreme Court decisions and Notes addressing legislative history in Chapter Seven (Bittner v. United States and Delaware v. Pennsylvania).

The Supplement further includes treatment of a number of recent Supreme Court decisions in Chapter 8 on appointment and removal (from Seila Law LLC v. Consumer Finance Protection Bureau, to Axon Enterprises v. Federal Trade Commission); on notice and comment rulemaking (Federal Communications Commission v. Prometheus Radio Project); and on judicial review of agency rules (Department of Homeland Security v. Regents of the Univ. of California and Biden v. Texas); as well as an extended Note on executive orders and the regulatory process in the Trump and Biden eras. Finally, the Supplement covers the major questions doctrine in depth (NFIB v. OSHA, Biden v. Missouri, West Virginia v. EPA, Biden v. Nebraska, and Sackett v. EPA) in Chapter 9.