Justices on the United States Supreme Court use rhetorical strategies to maintain institutional legitimacy. In the court opinion, a strategy called the monologic voice presents a flattering depiction of the Court. The monologic voice occurs through two tones, the individualistic and collective, which respectively maintain the Justices’ legitimacy through critique and the Court’s legitimacy through unification. We train large language models to identify these rhetorical features in 15,291 modern Supreme Court opinions, issued between 1946 and 2022. While the fraction of collective and individualistic tones has been relatively consistent between 1946 and 2022, the Rehnquist Court used the collective tone at a higher rate than any other Court. In recent terms, 2021 and 2022, we find suggestions of another rhetorical shift, as all Associate Justices of the Roberts Court, excluding Chief Justice Roberts, used the individualistic tone at a historically high rate.