FiveThirtyEight features John Kastellec in an examination of how the lack of diversity among judges affects how the judiciary is viewed and judicial outcomes: It Will Be Tough For Biden To Reverse Trump’s Legacy Of A Whiter, More Conservative Judiciary. Kastellec is associate professor of politics and CSDP faculty associate at Princeton University.

There’s also evidence that having more racial and gender diversity among federal judges actually influences the kinds of decisions that are made. This dynamic tends to emerge in cases involving race or gender issues — like affirmative action, voting rights, or employment discrimination — which might not make up the bulk of any given court’s docket but can still be consequential. In one study, for instance, Kastellec found that in cases related to affirmative action, the presence of a single randomly assigned Black judge on a three-judge appeals court panel¹ resulted in a more liberal outcome, independent of the judges’ political ideology. In fact, Kastellec told us, 'the effect of adding one Black judge was greater than the effect of adding two Democratic white judges.'