Drawing on data from every Supreme Court Term between 1940 and 2017, this Article revisits, updates, and expands prior empirical work by Ryan Owens and David Simon (2012) finding that ideological, contextual, and institutional factors contributed to the Court’s declining docket. This Article advances Owens and Simon’s work in three ways: broadening the scope of the study by including nine additional Court Terms (through 2017), adding alternative ideological and nonideological variables into the model, and considering alternative model specifications. What emerges from this update and expansion, however, is less clarity and more granularity and complexity. While Owens and Simon emphasized the salience of ideological distance across Justices as well as ideological distance separating the Supreme Court from the lower federal appellate courts, results from our study, by contrast, suggest that when it comes to ideological differences, intra-Court rather than intercourt ideological distance emerged, on balance, as critical. Other variables also emerged as persistently important, notably Congress’s decision in 1988 to remove much of the Court’s mandatory appellate jurisdiction and variation in the total number of certiorari petitions filed. Finally, these core findings appear robust across alternative model specifications. While most commentators react to a diminishing Court docket by emphasizing possible adverse consequences, rather than commit to any normative position, our Article instead considers both the possible institutional costs and benefits incident to a declining Court docket, with an emphasis on structural horizontal separation of powers implications