New Supreme Court justices are big news, and rightfully so. However, relatively little attention has been given to how changes in membership impact the decisions people make to engage with the Court. Until now. Kirsten Widner and Anna Gunderson take up this important question in their book, The Haves and Have-Nots in Supreme Court Representation and Participation, 2016 to 2021. They leverage an impressive amount of original data to trace changes in Supreme Court participation as the Court grew increasingly conservative with each of the three new justices added by President Trump during his first term. In a carefully theorized, accessible, and compelling page-turner, Widner and Gunderson explore how the changing nature of the Court affected decisions of both litigants and amici based on their level of political disadvantage, repeat player status, and ideology.

The authors first examine patterns in who petitions the Supreme Court for certiorari. As expected, those who are politically disadvantaged through both low levels of power and negative perceptions of their worthiness file fewer petitions over the relevant time frame. A similar decrease is seen among in forma pauperis petitioners (i.e., those whose lack of resources has qualified them to file without the usual fee). Republican-governed states filed more petitions over time. These trends ar